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Hello, everyone, and thank you for tuning in to Help
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for HD Live. This podcast is made possible by Teva Pharmaceuticals,
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Neurocrime Biosciences, Sarepta, Unicure, and the Griffin Foundation. I will
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be your host today, Katie Jackson. And today, our guest
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is Wes. Wes is a certified genetic counselor and the
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director of HD Genetics, as a lot of us know,
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a remote genetic counseling and testing option for the HD community.
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So it's now going on its fourth year. Yeah, Wes?
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Yeah, four years.
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Four years. Four years. Think about the amount of families
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that you guys have helped and pushing forward. And it's
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pretty incredible that we have this option now available to us.
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But let's dive in a little bit about a couple
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of subjects. And Wes has agreed to do this, do
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two shows. So he's going to do this show on
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the first week of October, and it'll also be on
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the third week of October for us. So that's pretty
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cool he's given us. a little bit of his time
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to go through and talk about this because I know
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he's very busy. So we'll get started. And let's talk
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about timing of testing. So how do you help patients
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decide when is the right time to get tested for
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Huntington's disease, especially if they're not showing any symptoms?
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Yeah, that's a great question. And that's a term that
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folks may hear thrown around referred to as predictive genetic testing,
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whenever they're thinking about testing for HD and maybe talking
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with a genetic counselor or talking with their provider about testing.
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And there's not really one answer to that question. I
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think that it can feel like a non-answer to receive
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the response that it's really to each individual, what's best
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for them. And to get more to a place of
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satisfying that, I would say, Thinking about all the possible
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outcomes of the test, let's imagine that you're going to
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undergo testing for Huntington's disease. Let's think about the possibility
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that test comes back positive, meaning you did inherit that
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genetic cause of Huntington's disease. Let's think if it comes
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back negative, how does that feel for you? And then also,
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what if it comes back somewhere in between? What if
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it's in the gray area and we're not really sure
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if that leads to you developing Huntington's disease or not?
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Sometimes that's a new concept for people and sometimes they're
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already familiar with it. But when we're thinking about these
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possible pathways forward, I think if you can envision any
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of those outcomes and you can think about what does
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my life look like regardless of what this result looks like,
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then I think that's a good place to start whenever
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we're thinking about testing for HD and what that could
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look like for them. I think it's also important though
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to add another option, which is what if I don't test?
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What if I just give myself Some more time. What
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if I draw some time down the line? I pick
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a date. I revisit this question. Do I want to
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test now? What is it about right now? Is this
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the time? I think thinking about those four possibilities, positive, negative,
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gray area, or just waiting and thinking about what that
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looks like for your future. I think that's a good
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place to start.
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Yeah, absolutely. And I think it's interesting what you said
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about the waiting. My kids were like so excited. very
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certain of their HD journey. They were like 15, right?
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Like I'm getting tested at 18. That was my oldest.
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When I turned 18, the day I turned 18, I'm
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going and I'm getting tested. And she waited five years.
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And I think the big thing is to give yourself,
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let yourself forgive. You don't have to make any decisions.
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This is about you. Even if you tell your whole family,
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this is what I'm doing. And you think, oh, well,
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they're counting on me. It's not about them. It's about
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your journey. And that can change, right? Just like what
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you said.
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Absolutely.
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Yeah.
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I think sometimes people feel a sense of pressure, whether
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that's external pressure or it's actually internal pressure where, like
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you said, they picked a date. They've been saying for
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so long that as soon as they turn 18, they
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want to test. And then 18 is coming up and
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they're like, what if I don't want to test? You
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know what? That's totally okay. You can change your mind.
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There's no rules here. There's no judgments. It's entirely your
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decision and what is best for you. And no one's
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going to hold it against you if you say, you
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know what, maybe not right now.
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Yeah, no, absolutely. And how can you receive your test
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results at different stages of life? So as such as
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a young adult versus later in life, does it affect
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someone's experience or decisions?
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Yeah, that's a really great question. Just as we're talking
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about this example of someone maybe turning 18 and very
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early in their adulthood, testing versus maybe someone way older
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in later years of their life. I've encountered folks from
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all ages that have considered testing or have gone through
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with the entire process of testing. And I think it
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just further illustrates that point that it really is an
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individual process. It really is up to that individual what's
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best for them. And some people, they are very young
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and they just know and they just want a test
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and they just want that information. They want to move
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forward and they may face some resistance from whether that's
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family or community or industry or whatever you want to
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say as far as being told that maybe they're too
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young to know, but they just know that they want
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to know. That's fine. That's also something to consider that
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if you just know in your heart of hearts that
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you just want this information to move forward, that's of
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course okay. There are things to consider if you're going
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to do that, maybe lasting effects if you were to test,
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but it's also okay if you don't want to know
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and you wait for years and years, decades, and you
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get later in life and you decide one of the
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common things is, I don't want to know until maybe
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I'm developing symptoms. Then you If that's the case, if
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I'm actually really feeling like, oh, maybe I am, and
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maybe this is something to consider. And then that's your
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benchmark of when you want to know that's fine, too.
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I think it's just really important to drive home that
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it's entirely up to you and what's best for you.
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Yeah, I'm curious about something. So when you have these
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young adults coming to you, I would assume that they
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would like, not really have any expectations, like maybe I'm positive,
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maybe I'm negative, they may be playing these like kind
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of scenarios in their head. But when you have someone
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older in life coming in, have you ever experienced or
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see that they're like, I'm older than my brother or
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my sister. And so I'm negative. Anyways, I'm just confirming
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this with you.
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Yeah, that's a really tricky one. I'm glad you brought
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that up, Katie, because it does happen that folks maybe
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feel like they've outlived that year that they would develop symptoms.
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And so they're like you said, trying to confirm that
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they have a negative result. And that's a tricky one
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because if you have an affected parent, you are at
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a 50-50 risk of inheriting that genetic cause of HD.
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And we don't know what age you would develop symptoms.
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And sometimes there really are undeniable patterns in families where
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it really is like generation after generation, it looks like
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someone is developing symptoms at the same age. But that
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is not ironclad concrete. In fact, two members of the
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same family can have the same CAG repeat number, but
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still develop symptoms at different ages. And they can present
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differently in those two different individuals. So it's really tough.
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And that's where genetic counseling can really come in handy.
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That's a good example. It's basically someone coming into this
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feeling like they know the outcome of the test. I
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think either way, whatever someone is convinced it's going to
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be positive or they're convinced it's going to be negative,
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it's important to explore the possibilities, the other possibilities of
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outcomes there and manage expectations.
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Yeah, that makes sense. So let's talk about the testing
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process itself. So what types of genetic tests are available
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for Huntington's disease?
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That's a great question, too. So historically, testing for Huntington's
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disease and actually genetic testing in general is often referred
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to as blood testing or going to get the blood
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test or getting the test for Huntington's is a guy
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go get my blood drawn. True, right? A lot of
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genetic testing was done by blood historically. And currently, still,
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you can still do that. There are other options. You
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can also get a saliva test. You can use your
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saliva sample to test for HD. It's going to look
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for the same thing, which is what we call a
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germline mutation, meaning it's something that you're born with that
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goes throughout all the cells of your body. So we
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can detect those CAG repeats as we talk about with
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Huntington's disease. So blood, saliva, you can also do a
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cheek swab if you want, which is sometimes referred to
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as a buccal swab, which is a fancy word for
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cheek swab.
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Okay. And how accurate are these tests for Huntington's disease?
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Yeah, great question. So these tests are extremely accurate. They're
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over 99% accurate. The saliva test is comparable in accuracy
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to that blood test. Sometimes people are kind of weighing
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those two options and they're like, maybe I should get
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the blood test because that's going to be better, quote unquote,
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or it's going to be more accurate. There are differences
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in these samples, but they're more like nuts and bolts differences.
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You can get more DNA per volume with blood than
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you can with saliva. But that is a little irrelevant
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when we're talking about testing for Huntington's disease. So when
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you detect what you need to detect with Huntington's, which
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is specifically the CAG repeats in the Huntington gene, you
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can detect that with saliva. And once you've got it,
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you've got it. With blood, once you've got it, you've
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got it too. And having this more DNA per volume
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with blood, you end up having this excess of DNA.
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So it's not really relevant to have more DNA here
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and have a certain amount here. It's really, are we
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detecting what we need to detect?
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So, and final question for this episode that we're going
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to do is, can you explain what it means for
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someone testing positive, negative, and gray zone results? And if
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we could even get in a little deeper in the
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different parts of the different types of gray zone results.
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Absolutely. Yeah. So the way that I describe this is
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basically that when you if and when you are thinking
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about genetic testing for Huntington's disease, I say that this
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is a genetic test that's going to look at your DNA.
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And I describe DNA as being essentially the set of
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instructions for your body. And those instructions, if you kind
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of take that analogy a little further, think about it
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as like an instruction manual divided up into chapters. And
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the chapters represent the genes of your DNA. With Huntington's
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disease specifically, we're really concerned about this one gene called
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the Huntington gene. And if you were to open up
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your instruction manual of DNA, you'd of course see a
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bunch of words on the page making up those instructions,
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but you'd see one word specifically repeated over and over again.
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And that word would say CAG, CAG, CAG, et cetera.
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And that's what we're talking about with these CAG repeats.
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That's actually okay. we expect to see the CAG repeat
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in the Huntington gene. It's only when there are too
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many CAGs that we get concerned about Huntington's disease. So
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if you were to undergo genetic testing for Huntington's disease,
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what you get back on your test report is actually
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two CAG repeat count numbers. And that's because we all
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have two copies of that Huntington gene, one that we've
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inherited from biological mother, the other that we've inherited from
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biological father. If both of those numbers come back as
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being less than 27, so you have 26 or fewer
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CAGs from mom, and you have 26 or fewer CAGs
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from dad, that is what we call a normal or
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negative test result, meaning you're not at risk for Huntington's disease,
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and any children that you may have would not be
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at risk for Huntington's disease, at least not from your
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genetic lineage. However, if you were to have a genetic
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test report come back and say at least one copy
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of your Huntington genes has 40 or more CAGs, that
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would be what we refer to as full penetrance Huntington's disease,
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meaning at some point in your life, you would develop Huntington's.
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And each of your children, if you had children, would
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be at a 50-50 risk of inheriting that genetic cause
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of Huntington's disease. Now, the tricky part, the rare possibility,
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but a possibility nonetheless, is that test report can come
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back with a copy of the gene where that CAG
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repeat is actually somewhere in between those numbers. And this
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could be somewhere between 27 to 39. And as you
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described it, Katie, it's basically what we refer to conversationally
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as the gray area or the gray zone. And that's
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what it sounds like, where we're not really sure whether
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you would develop Huntington's disease. It does get clearer depending
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on the number that you get back. So this gets
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broken down into two smaller categories. If your tests were
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to come back with a copy of the gene where
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that CAG is somewhere between 36 to 39, that would
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be what we call reduced penetrance. And basically the idea
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there is, again, we don't know whether you would develop
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Huntington's disease, but if you did, develop symptoms of Huntington's,
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and you had a CAG somewhere in between there, 36, 37, 38, 39.
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Sometimes folks that have a CAG in that range may
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develop symptoms later in life, or maybe those symptoms are
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milder and later in life. And that's what we refer
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to as reduced penetrance. That's where that category is called reduced,
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whereas full penetrance is 40 and above, meaning we know
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that you would develop HD. Reduced penetrance at 36 to 39,
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we're not really sure. Now, the last category is if
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your test came back with a copy of the gene
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where that CAG was somewhere between 27 to 35, that
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would be what we call intermediate. And basically the take
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home there is that it would be extremely unlikely for
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you to develop Huntington's disease. In fact, we would not
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be concerned about you developing Huntington's disease. What we are
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concerned about though, with any copy of the gene that
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has a CAG of 27 or more, is as that
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number is a higher and higher number past that threshold
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of 27, there's more and more of a risk that
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if that copy of the gene were to be passed
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down to offspring, for the offspring that inherits that copy
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of the gene, their CAG repeat number could be different,
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meaning it could be a little smaller or it could
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actually be bigger. It could be a bigger CAG repeat expansion.
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And that would be our concern because then that would
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mean a higher risk of Huntington's disease for that offspring
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that inherited that larger CAG repeat expansion. Yeah.
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Thank you so much, Wes, for coming on and talking
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to us about these two, time of testing and the
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testing process.
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Absolutely.
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Next show, we'll get into a little bit more about
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family impact and a little bit of the harder questions.
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But I think just knowing the basics is so confusing.
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These numbers get thrown around everywhere. And so thank you
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for applying some of that for sure. Thank you for
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all that you do. So I will actually close up
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the show and wrap. Again, thank you to all of
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our sponsors for making Help for HD live possible. And
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of course, thank you to HD Genetics for all that
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they're doing. And if you guys are feeling like you
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cannot afford testing and you really want to pursue genetic testing,
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definitely reach out to Wes. The first conversation is free.
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He can help you talk about what that looks like
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for you financially to be able to help you through
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the process. So on that note, everyone, we'll see you
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down the road.
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Hello, everyone, and thank you for tuning in to Help
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for HD Live. This podcast is made possible by Teva Pharmaceuticals,
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Neurocrime Biosciences, Sarepta, Unicure, and the Griffin Foundation. I will
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be your host today, Katie Jackson. And today, our guest
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is Wes. Wes is a certified genetic counselor and the
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director of HD Genetics, as a lot of us know,
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a remote genetic counseling and testing option for the HD community.
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So it's now going on its fourth year. Yeah, Wes?
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Yeah, four years.
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Four years. Four years. Think about the amount of families
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that you guys have helped and pushing forward. And it's
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pretty incredible that we have this option now available to us.
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But let's dive in a little bit about a couple
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of subjects. And Wes has agreed to do this, do
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two shows. So he's going to do this show on
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the first week of October, and it'll also be on
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the third week of October for us. So that's pretty
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cool he's given us. a little bit of his time
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to go through and talk about this because I know
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he's very busy. So we'll get started. And let's talk
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about timing of testing. So how do you help patients
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decide when is the right time to get tested for
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Huntington's disease, especially if they're not showing any symptoms?
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Yeah, that's a great question. And that's a term that
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folks may hear thrown around referred to as predictive genetic testing,
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whenever they're thinking about testing for HD and maybe talking
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with a genetic counselor or talking with their provider about testing.
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And there's not really one answer to that question. I
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think that it can feel like a non-answer to receive
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the response that it's really to each individual, what's best
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for them. And to get more to a place of
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satisfying that, I would say, Thinking about all the possible
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outcomes of the test, let's imagine that you're going to
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undergo testing for Huntington's disease. Let's think about the possibility
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that test comes back positive, meaning you did inherit that
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genetic cause of Huntington's disease. Let's think if it comes
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back negative, how does that feel for you? And then also,
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what if it comes back somewhere in between? What if
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it's in the gray area and we're not really sure
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if that leads to you developing Huntington's disease or not?
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Sometimes that's a new concept for people and sometimes they're
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already familiar with it. But when we're thinking about these
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possible pathways forward, I think if you can envision any
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of those outcomes and you can think about what does
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my life look like regardless of what this result looks like,
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then I think that's a good place to start whenever
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we're thinking about testing for HD and what that could
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look like for them. I think it's also important though
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to add another option, which is what if I don't test?
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What if I just give myself Some more time. What
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if I draw some time down the line? I pick
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a date. I revisit this question. Do I want to
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test now? What is it about right now? Is this
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the time? I think thinking about those four possibilities, positive, negative,
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gray area, or just waiting and thinking about what that
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looks like for your future. I think that's a good
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place to start.
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Yeah, absolutely. And I think it's interesting what you said
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about the waiting. My kids were like so excited. very
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certain of their HD journey. They were like 15, right?
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Like I'm getting tested at 18. That was my oldest.
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When I turned 18, the day I turned 18, I'm
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going and I'm getting tested. And she waited five years.
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And I think the big thing is to give yourself,
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let yourself forgive. You don't have to make any decisions.
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This is about you. Even if you tell your whole family,
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this is what I'm doing. And you think, oh, well,
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they're counting on me. It's not about them. It's about
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your journey. And that can change, right? Just like what
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you said.
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Absolutely.
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Yeah.
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I think sometimes people feel a sense of pressure, whether
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that's external pressure or it's actually internal pressure where, like
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you said, they picked a date. They've been saying for
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so long that as soon as they turn 18, they
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want to test. And then 18 is coming up and
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they're like, what if I don't want to test? You
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know what? That's totally okay. You can change your mind.
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There's no rules here. There's no judgments. It's entirely your
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decision and what is best for you. And no one's
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going to hold it against you if you say, you
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know what, maybe not right now.
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Yeah, no, absolutely. And how can you receive your test
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results at different stages of life? So as such as
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a young adult versus later in life, does it affect
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someone's experience or decisions?
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Yeah, that's a really great question. Just as we're talking
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about this example of someone maybe turning 18 and very
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early in their adulthood, testing versus maybe someone way older
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in later years of their life. I've encountered folks from
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all ages that have considered testing or have gone through
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with the entire process of testing. And I think it
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just further illustrates that point that it really is an
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individual process. It really is up to that individual what's
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best for them. And some people, they are very young
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and they just know and they just want a test
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and they just want that information. They want to move
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forward and they may face some resistance from whether that's
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family or community or industry or whatever you want to
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say as far as being told that maybe they're too
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young to know, but they just know that they want
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to know. That's fine. That's also something to consider that
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if you just know in your heart of hearts that
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you just want this information to move forward, that's of
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course okay. There are things to consider if you're going
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to do that, maybe lasting effects if you were to test,
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but it's also okay if you don't want to know
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and you wait for years and years, decades, and you
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get later in life and you decide one of the
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common things is, I don't want to know until maybe
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I'm developing symptoms. Then you If that's the case, if
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I'm actually really feeling like, oh, maybe I am, and
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maybe this is something to consider. And then that's your
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benchmark of when you want to know that's fine, too.
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I think it's just really important to drive home that
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it's entirely up to you and what's best for you.
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Yeah, I'm curious about something. So when you have these
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young adults coming to you, I would assume that they
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would like, not really have any expectations, like maybe I'm positive,
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maybe I'm negative, they may be playing these like kind
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of scenarios in their head. But when you have someone
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older in life coming in, have you ever experienced or
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see that they're like, I'm older than my brother or
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my sister. And so I'm negative. Anyways, I'm just confirming
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this with you.
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Yeah, that's a really tricky one. I'm glad you brought
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that up, Katie, because it does happen that folks maybe
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feel like they've outlived that year that they would develop symptoms.
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And so they're like you said, trying to confirm that
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they have a negative result. And that's a tricky one
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because if you have an affected parent, you are at
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a 50-50 risk of inheriting that genetic cause of HD.
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And we don't know what age you would develop symptoms.
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And sometimes there really are undeniable patterns in families where
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it really is like generation after generation, it looks like
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someone is developing symptoms at the same age. But that
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is not ironclad concrete. In fact, two members of the
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same family can have the same CAG repeat number, but
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still develop symptoms at different ages. And they can present
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differently in those two different individuals. So it's really tough.
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And that's where genetic counseling can really come in handy.
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That's a good example. It's basically someone coming into this
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feeling like they know the outcome of the test. I
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think either way, whatever someone is convinced it's going to
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be positive or they're convinced it's going to be negative,
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it's important to explore the possibilities, the other possibilities of
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outcomes there and manage expectations.
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Yeah, that makes sense. So let's talk about the testing
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process itself. So what types of genetic tests are available
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for Huntington's disease?
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That's a great question, too. So historically, testing for Huntington's
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disease and actually genetic testing in general is often referred
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to as blood testing or going to get the blood
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test or getting the test for Huntington's is a guy
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go get my blood drawn. True, right? A lot of
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genetic testing was done by blood historically. And currently, still,
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you can still do that. There are other options. You
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can also get a saliva test. You can use your
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saliva sample to test for HD. It's going to look
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for the same thing, which is what we call a
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germline mutation, meaning it's something that you're born with that
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goes throughout all the cells of your body. So we
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can detect those CAG repeats as we talk about with
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Huntington's disease. So blood, saliva, you can also do a
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cheek swab if you want, which is sometimes referred to
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as a buccal swab, which is a fancy word for
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cheek swab.
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Okay. And how accurate are these tests for Huntington's disease?
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Yeah, great question. So these tests are extremely accurate. They're
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over 99% accurate. The saliva test is comparable in accuracy
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to that blood test. Sometimes people are kind of weighing
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those two options and they're like, maybe I should get
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the blood test because that's going to be better, quote unquote,
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or it's going to be more accurate. There are differences
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in these samples, but they're more like nuts and bolts differences.
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You can get more DNA per volume with blood than
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you can with saliva. But that is a little irrelevant
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when we're talking about testing for Huntington's disease. So when
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you detect what you need to detect with Huntington's, which
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is specifically the CAG repeats in the Huntington gene, you
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can detect that with saliva. And once you've got it,
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you've got it. With blood, once you've got it, you've
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got it too. And having this more DNA per volume
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with blood, you end up having this excess of DNA.
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So it's not really relevant to have more DNA here
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and have a certain amount here. It's really, are we
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detecting what we need to detect?
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So, and final question for this episode that we're going
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to do is, can you explain what it means for
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someone testing positive, negative, and gray zone results? And if
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we could even get in a little deeper in the
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different parts of the different types of gray zone results.
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Absolutely. Yeah. So the way that I describe this is
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basically that when you if and when you are thinking
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about genetic testing for Huntington's disease, I say that this
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is a genetic test that's going to look at your DNA.
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And I describe DNA as being essentially the set of
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instructions for your body. And those instructions, if you kind
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of take that analogy a little further, think about it
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as like an instruction manual divided up into chapters. And
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the chapters represent the genes of your DNA. With Huntington's
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disease specifically, we're really concerned about this one gene called
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the Huntington gene. And if you were to open up
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your instruction manual of DNA, you'd of course see a
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bunch of words on the page making up those instructions,
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but you'd see one word specifically repeated over and over again.
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And that word would say CAG, CAG, CAG, et cetera.
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And that's what we're talking about with these CAG repeats.
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That's actually okay. we expect to see the CAG repeat
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in the Huntington gene. It's only when there are too
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many CAGs that we get concerned about Huntington's disease. So
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if you were to undergo genetic testing for Huntington's disease,
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what you get back on your test report is actually
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two CAG repeat count numbers. And that's because we all
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have two copies of that Huntington gene, one that we've
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inherited from biological mother, the other that we've inherited from
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biological father. If both of those numbers come back as
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being less than 27, so you have 26 or fewer
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CAGs from mom, and you have 26 or fewer CAGs
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from dad, that is what we call a normal or
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negative test result, meaning you're not at risk for Huntington's disease,
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and any children that you may have would not be
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at risk for Huntington's disease, at least not from your
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genetic lineage. However, if you were to have a genetic
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test report come back and say at least one copy
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of your Huntington genes has 40 or more CAGs, that
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would be what we refer to as full penetrance Huntington's disease,
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meaning at some point in your life, you would develop Huntington's.
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And each of your children, if you had children, would
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be at a 50-50 risk of inheriting that genetic cause
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of Huntington's disease. Now, the tricky part, the rare possibility,
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but a possibility nonetheless, is that test report can come
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back with a copy of the gene where that CAG
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repeat is actually somewhere in between those numbers. And this
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could be somewhere between 27 to 39. And as you
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described it, Katie, it's basically what we refer to conversationally
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as the gray area or the gray zone. And that's
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what it sounds like, where we're not really sure whether
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you would develop Huntington's disease. It does get clearer depending
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on the number that you get back. So this gets
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broken down into two smaller categories. If your tests were
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to come back with a copy of the gene where
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that CAG is somewhere between 36 to 39, that would
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be what we call reduced penetrance. And basically the idea
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there is, again, we don't know whether you would develop
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Huntington's disease, but if you did, develop symptoms of Huntington's,
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and you had a CAG somewhere in between there, 36, 37, 38, 39.
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Sometimes folks that have a CAG in that range may
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develop symptoms later in life, or maybe those symptoms are
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milder and later in life. And that's what we refer
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to as reduced penetrance. That's where that category is called reduced,
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whereas full penetrance is 40 and above, meaning we know
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that you would develop HD. Reduced penetrance at 36 to 39,
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we're not really sure. Now, the last category is if
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your test came back with a copy of the gene
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where that CAG was somewhere between 27 to 35, that
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would be what we call intermediate. And basically the take
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home there is that it would be extremely unlikely for
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you to develop Huntington's disease. In fact, we would not
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be concerned about you developing Huntington's disease. What we are
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concerned about though, with any copy of the gene that
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has a CAG of 27 or more, is as that
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number is a higher and higher number past that threshold
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of 27, there's more and more of a risk that
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if that copy of the gene were to be passed
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down to offspring, for the offspring that inherits that copy
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of the gene, their CAG repeat number could be different,
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meaning it could be a little smaller or it could
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actually be bigger. It could be a bigger CAG repeat expansion.
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And that would be our concern because then that would
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mean a higher risk of Huntington's disease for that offspring
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that inherited that larger CAG repeat expansion. Yeah.
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Thank you so much, Wes, for coming on and talking
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to us about these two, time of testing and the
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testing process.
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Absolutely.
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Next show, we'll get into a little bit more about
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family impact and a little bit of the harder questions.
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But I think just knowing the basics is so confusing.
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These numbers get thrown around everywhere. And so thank you
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for applying some of that for sure. Thank you for
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all that you do. So I will actually close up
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the show and wrap. Again, thank you to all of
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our sponsors for making Help for HD live possible. And
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of course, thank you to HD Genetics for all that
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they're doing. And if you guys are feeling like you
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cannot afford testing and you really want to pursue genetic testing,
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definitely reach out to Wes. The first conversation is free.
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He can help you talk about what that looks like
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for you financially to be able to help you through
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the process. So on that note, everyone, we'll see you
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down the road.
