If one of your parents has HD, you have a 50% chance of carrying the gene. Testing can tell you definitively. But the decision to test — or not — is one of the most personal choices a person can make. Here is what you need to know.
You are reading this because someone in your family has Huntington's Disease. Maybe a parent. Maybe a grandparent. And now you are sitting with a question that only you can answer.
Do I want to know?
There is no right answer. This guide will not tell you what to do. What it will do is make sure you understand every option available to you — so that whatever you decide, you decide it clearly.
What Is Genetic Testing for HD?
Huntington's Disease is caused by an expansion of the CAG repeat in the HTT gene on chromosome 4. A blood test can count the number of repeats and determine:
- Below 27 repeats: Will not develop HD, cannot pass HD to children
- 27–35 repeats: Will not develop HD, but children may be at increased risk
- 36–39 repeats: May or may not develop HD (reduced penetrance)
- 40 or more repeats: Will develop HD
Type 1: Predictive Testing for Adults at Risk
Predictive testing is available to any adult whose parent has — or had — HD. You do not need symptoms to be tested. You simply need to be an adult making an informed decision.
What it involves:
- Blood draw at a genetics lab
- Analysis of CAG repeat count
- Results delivered through a genetic counselor (not by mail, not alone)
"The decision to learn your genetic status is irreversible. You cannot unknow what you know. That is not a reason not to test — but it is a reason to test thoughtfully."
Who chooses to test: Research suggests only about 5–10% of at-risk adults eventually undergo predictive testing. The majority choose to live without that information. Both choices are valid and the genetic counseling process is designed to support either path.
Type 2: Testing During Pregnancy
If you are pregnant and one parent carries the HD gene, two options exist for the pregnancy:
Standard Prenatal Testing
Tests the fetus directly — either through chorionic villus sampling (CVS) in the first trimester or amniocentesis in the second. If the fetus carries the expanded gene, the couple must decide how to proceed.Non-Disclosure Prenatal Testing
This testing protocol tests whether the fetus has inherited the chromosome from the at-risk parent — without revealing the parent's own status. If the fetus has not inherited the at-risk chromosome, the pregnancy continues. If it has, the couple is informed that the fetus is at the same risk as the parent, without knowing the parent's actual status.This complex option preserves the parent's right not to know their own genetic status while still providing actionable information about the pregnancy.
Type 3: IVF with Preimplantation Genetic Testing (PGT-M)
This is the most powerful option available to at-risk adults who are building — or planning to build — a family.
With IVF and PGT-M:
The result: The HD mutation stops with your generation. Your children and grandchildren will never face this choice.
The barrier: Cost. A full IVF cycle with PGT-M typically costs $15,000–$25,000, and insurance coverage is inconsistent.
This is precisely the barrier that NVforHD's 2024 charity partner HelpCureHD was built to remove. They provide grants to HD families who cannot afford IVF. Read how $25,000 from our golf tournament funded the Puccini family's IVF journey.
How to Access Testing in Northern Nevada
The nearest HD genetic counselor to Reno is at the UC Davis HD Center of Excellence in Sacramento — NVforHD's 2025 and 2026 beneficiary. The drive is 130 miles.
The UC Davis HD genetic counselor provides:
- Pre-test and post-test counseling for predictive testing
- Non-disclosure prenatal testing coordination
- IVF/PGT-M referrals and guidance
- Family support throughout the process
Questions to Sit With
Before making a decision about testing, HDSA recommends families consider:
- How would a positive result change the decisions I am making right now?
- Who is in my support network — who would I tell, and how?
- Am I testing for myself, or for someone else?
- What would I do differently if I tested negative?
"The genetic counselor's job is not to push you toward testing. It is to make sure that whatever you decide, you decide it with full information and genuine support."
Contact NVforHD if you are an HD family in Northern Nevada. We are not a counseling service — but we are an HD family who has navigated these exact questions. We will help you find the right support.
📞 775-691-8860 · Contact us here
