If you or someone you love is affected by hypohidrotic ectodermal dysplasia (HED), a doctor or dentist may have made the clinical diagnosis based on symptoms. Or, maybe HED runs in your family and you “just know” that you or your child have it. So, why would you want to get genetic testing to confirm the diagnosis? There are many benefits. But, most importantly because the first treatment for the X-linked recessive type of HED is being studied in a clinical trial.
A genetic diagnosis will help you have a better understanding of your condition.
A genetic test result will help a genetics specialist provide more accurate counseling, guidance, and management for you and your family. HED can be inherited in three different ways: X-linked recessive, autosomal recessive, and autosomal dominant. Despite these differences, the symptoms of HED are generally the same for each, but may vary in severity or presentation depending on if someone is a male or female. A genetic counselor can explain to you what symptoms to expect for the type of HED that you have.
The biggest difference between the forms of inheritance is the way in which the gene can be passed from an affected parent to a child. The most common type is the X-linked recessive variation, called XLHED. It is caused by changes (also called variants) in the EDA gene. This gene is located on the X chromosome, so females and males may have slightly different features. Knowing your specific genetic diagnosis will allow the genetics specialist to provide accurate recurrence risk information, the chances of passing on the condition to each child, while also discussing different reproductive options that are available.
A genetic diagnosis will gain you access to research studies.
EspeRare and Pierre Fabre have launched an international clinical trial, called EDELIFE, to investigate the first real treatment for XLHED, called ER-004. According to the EDELIFE website, “the clinical trial is open to pregnant women who have not yet reached the 23rd week of pregnancy, have a genetic confirmation of their XLHED status and have their unborn son affected.”
Early results show that the treatment has restored sweating and had other positive affects in several baby boys affected by XLHED.
The windows to treat the baby in utero is a small one. If a pregnant mom is interested in being in the study, she must have a genetic test confirming that she has XLHED.
We are hopeful to have more research studies in the future for potential treatments. To potentially participate in those, you will need a genetic diagnosis since some research studies may be focused on certain genes or variants in those genes.
Planning to Be Pregnant?
If you are a woman affected by XLHED, are planning to be pregnant in the next few years, and interested in joining the EDELIFE study, you may want to meet with a genetic counselor now to have preconception genetic counseling. During the appointment, the genetic counselor will review your personal and family history and discuss genetic testing and/or reproductive options. To find a genetic counselor in your area, visit the National Society of Genetic Counselors or contact the NFED. This will help you in the process of applying to be in the study.
The genetic testing process can take time. It may take time to get an appointment with the geneticist to order the test, for insurance to approve testing, and to get the results back. Having a genetic diagnosis before pregnancy can help assure that you would not miss the treatment window if you are accepted into the study.
It is our hope that the clinical study will confirm the positive results and that ER-004 will be available on the market by 2026. Getting tested now will help you in that process.
How We Can Help You Get Testing
The cost for genetic testing can vary. Check with your insurance company first to see if it is covered. The NFED does provide stipends to help cover costs. Learn more and apply to the Treatment Assistance Program.
What genetic testing will not show.
- Genetic testing will not be able to tell you whether or not you will show symptoms or which symptoms you will definitively experience.
- Genetic testing will not be able to tell you how severe the symptoms will be.
- Genetic testing may not find all genetic changes that cause HED.
Genetic testing can help identify family members who are suspected to be affected.
Typically, males who are affected by XLHED fully express symptoms, although those systems may vary between males. Females with XLHED are often called carriers because they may show no symptoms or very mild symptoms. Even within a family, the range of symptoms can vary greatly. One sister with the genetic variant may have many mild symptoms while her affected sister may not have any symptoms. But, they both have the same chance of passing that genetic change to a child. Genetic testing is the best way for a female to know if she does or does not carry the genetic variant that causes XLHED.
If you have an affected son and suspect a sibling may or may not be affected, too, genetic testing can confirm the diagnosis.
You may consider sharing this information with others in your family who may have XLHED. It may be a sensitive issue for some people. Talk with a genetic counselor about how to best share that kind of information with relatives.
We’re Here for You
We are excited to finally have a potential treatment for XLHED available for you and your family to consider. Our goal in providing this information is to help you prepare should you want to pursue treatment.
If you have any questions, you can contact me at mary@nfed.org.