Genetic counseling for muscular dystrophy (MD) can help you and your family get clarity, guidance, and emotional support when navigating a diagnosis.
MD is a broad term for a group of more than 30 inherited genetic disorders that cause progressive muscle weakness and loss of muscle control. MD results from mutations in genes that encode the proteins responsible for building and maintaining muscle tissue.
Each MD type is caused by a mutation in a different gene and has its own inheritance pattern. Knowledge about the genetics of each type of MD is crucial for assessing the risk of passing it to future generations.
What does a genetic counselor do?
Genetic testing for MD helps people understand the genetic cause of their condition and the potential risk of passing it on to children. It can also identify other family members who may carry the gene mutation, and may inform health or family planning decisions.
Genetic counselors, who are clinicians trained in human genetics, are the specialists who conduct these tests. However, genetic counselors do more than order lab tests. They can also:
- teach you or your family about MD and how it is inherited
- help with selecting and requesting the necessary testing panels
- help you get financial assistance or insurance authorization for testing
- translate complex genetic data into knowledge you or your family can use to navigate the disease
- advise you on how to discuss the genetic risk of MD with family members who might benefit from further testing
Genetic counseling should be non-directive. This means it is not the counselor’s job to tell you or your family what to do. Instead, the role of the counselor is to help you make decisions that are right for you.
When may genetic counseling be helpful?
Genetic counseling may be useful both before and after genetic testing, as well as for discussing the disease with family members who might be at risk or those planning on starting a family.
Before testing
Genetic counselors act as an interface between the patient and the clinician. As such a counselor can help by confirming whether you or a family member would benefit from genetic testing for MD, recommending the appropriate genetic tests needed to diagnose and confirm an MD type, and helping you or your loved ones understand the results of these tests.
After testing
After testing for MD, genetic counselors explain to individuals and their healthcare providers the likelihood that the disease will be passed to the next generation and how to communicate this to others. If you or another family member is at risk of passing on a gene that can lead to MD, a genetic counselor can help you or your loved one work out who needs to know and how to share the information.
When relatives might be at risk
An important aspect of genetic counseling is to offer emotional support to families. This includes making it easier to talk about the condition, such as helping to write a letter to at-risk relatives, working out ways to discuss it with families, and connecting at-risk family members with local genetic counseling services to explore their own risk and access family genetic testing.
When planning a family
Genetic counselors can provide referrals for community groups and support services to help you or your family members cope with the strong emotions connected to having children. They can also let you and your loved ones know the scope of clinical support that’s available to you while navigating the genetic risk of MD.
What happens during an appointment?
Before testing, a genetic counselor typically will start a session by asking about your medical history and any family history of MD. Inheritance counseling can help you or your family members calculate the risk of passing on the disease-causing gene and what this means for those who develop the condition.
To achieve this, counselors usually will map out the family tree, including non-immediate family such as aunts, uncles, cousins, and grandparents. This family tree will include information on any family members who developed MD, including:
- the type they had
- the age at which it developed
- whether they are still living
If your own medical history suggests a risk of MD, the counselor may use an assessment tool to determine the likely risk. Based on this, the counselor will discuss the benefits and risks of genetic testing, as well as the laws that protect privacy regarding genetic information. The counselor can also set up genetic testing appointments should you choose to pursue it.
After a test, the counselor will explain what your results mean, including whether they demonstrate a risk of developing MD. You will get a copy of the test results and a summary of what they mean.
The counselor will then help you plan for the future, which may include further testing, a discussion of treatment options, specialist referrals, and connections with support groups.
What can genetic test results mean?
Your genetic counselor can help you understand your genetic test results for MD. These test results do not mean that you will definitely have the disease or that you will definitely pass it on if you have children. But they can show whether you have a variant in a gene that will affect how the gene works.
The following table shows the different results you may receive.
Scroll horizontally to view all columns –>
| Genetic Test Result | What It Tells You |
|---|---|
| Positive | The test identified a disease-causing change in the gene, confirming a genetic diagnosis or carrier status. |
| Negative | The test did not detect a disease-causing variant. |
| Variant of uncertain significance (VUS) | The test found a DNA change, but current scientific and medical data cannot confirm whether or not it causes disease. |
| Inconclusive | The test could not yield a definitive positive or negative result, often due to sample quality, technical limitations, or unclear gene readouts. |
The next steps for you, following testing, depend on the results.
Positive results
By identifying a disease-causing gene change, this test result confirms a genetic diagnosis (e.g., Duchenne or Becker) or carrier status. Being a carrier means you have the gene mutation but do not have symptoms.
The test also identifies the exact mutation type.
You may want to discuss with your doctor whether the specific variant indicates a definitive clinical diagnosis and, if so, how the condition is likely to progress. A health professional may evaluate whether you are eligible for specific therapies or targeted clinical trials based on the mutation.
Your doctor may also offer cascade MD carrier testing to at-risk family members. For example, this may mean testing the mother first, then siblings or daughters for carrier status.
You may wish to join patient registry programs (such as The Duchenne Registry) to stay informed about relevant research updates.
Negative results
While testing did not detect a disease-causing gene variant, this does not entirely rule out a diagnosis — comprehensive testing detects approximately 95%-99% of cases. About 1%-5% of people with MD have gene alterations that standard testing methods cannot yet find.
If symptoms persist, a doctor may recommend a diagnostic muscle biopsy with immunoblot and immunostaining to assess dystrophin protein levels. Your doctor may also consider specialized tissue testing to evaluate gene transcription.
You should stay in contact with a neuromuscular center or genetic counselor. It may be possible to retest with newer genetic technologies over time.
Variant of uncertain significance (VUS)
With this result, although testing showed a DNA change, it’s not clear whether or not it causes disease. In such cases, the variant typically lacks a clearly established pattern of symptoms.
Still, you should not make major treatment decisions based only on a VUS.
Genetic counselors may test affected and unaffected family members to track whether the variant is linked to the condition elsewhere in the family.
You should consult your genetic counselor or testing laboratory to re-evaluate the variant as genomic databases are updated.
Inconclusive
Absent a definitive positive or negative result, a test’s findings may be labeled inconclusive. You may discuss with your doctor the idea of repeating the test with a fresh blood or saliva sample.
Your doctor may consider transitioning to a different, more comprehensive testing method, such as full-gene sequencing or deletion/duplication analysis.
You should discuss clinical symptoms and family history with a neuromuscular specialist to decide on alternative tests, if needed.
How can genetic counseling support family planning?
A genetic counselor can help you and your family understand your reproductive options with MD. This can help you consider:
- the risks to your own health
- the risks specific to pregnancy, including testing the fetus using amniocentesis or chorionic villus sampling (CVS)
- the genetic tests available for those planning to conceive, which can take place either during or before pregnancy
Genetic testing provides the bulk of guidance here, such as enabling immediate medical support for children born with congenital myotonic dystrophy. Genetic counseling can lay the groundwork for this testing, however, and help you or your loved ones work out which tests are available to you.
For example, preimplantation or prenatal testing is only available if certain mutations occur in the family. A genetic counselor can advise you if that mutation is present and help you arrange this testing.
How to prepare for an appointment
Preparing for genetic counseling involves gathering knowledge of your family’s medical history. Before the appointment, try to assemble:
- a three-generation family tree
- a list of relatives with confirmed MD, or with heart or lung conditions
- insurance information
- any questions you may have for the counselor
Gather any medical records that relate to or support your concerns. Alternatively, you or your relatives can ask a doctor to send these records to the genetic counselor before the consultation.
Questions to ask your genetic counselor
Speaking to a genetic counselor is a great opportunity to address your concerns about MD, finances, family planning, and treatment. Here’s a checklist of questions you can ask your genetic counselor.
- How is my specific MD type inherited?
- What is the risk that my relatives, children, or I will develop symptoms or be carriers?
- Who in my family should receive carrier testing or diagnostic screening?
- What are the test panel’s limitations, and what does a VUS mean?
- If standard testing is negative despite symptoms, what other tests are available?
- Will insurance cover testing? Are free or sponsored programs available?
- What sample is needed, and how long do results take?
- Will a genetic counselor review the results with me?
- Will the test identify the exact mutation and eligibility for targeted therapies or clinical trials?
- How will the genetic subtype affect cardiac and pulmonary care, and physical therapy?
- What monitoring do female carriers of X-linked MD need?
- What reproductive options are available based on our risk?
- How are results legally protected, and could they affect employment, or life and/or disability insurance?
Finding a genetic counselor
You can find a genetic counselor using the following resources:
- If you have a child with MD: Ask your child’s pediatrician or neurological care team for a referral. The neurological clinic may have one in-house.
- If you are a female with questions or concerns about having a child with MD or being a carrier: Ask your primary care physician or OB/GYN for a referral.
- If you need help finding a local genetic counselor: If you’re in the U.S. or Canada, you can use the Find a Genetic Counselor search tool.
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