How is Fabry disease inherited?
Fabry disease is passed through families in an X-linked inheritance pattern, meaning the GLA gene that causes Fabry disease is located on the X-chromosome. Women have two copies of the X-chromosome (XX) and men have one copy of the X-chromosome and one copy of a Y-chromosome (XY). If men inherit an X chromosome containing the non-working GLA gene, they are unable to produce alpha-Gal enzyme. Without alpha-Gal, GL-3 builds up in the body and causes the symptoms and health problems of Fabry disease. On the other hand, if women inherit an X chromosome with a nonworking GLA gene, they have a second X-chromosome with a working GLA gene that can produce some alpha-Gal enzyme. In the past, it was believed that women who were "carriers" would not have Fabry related health problems because they had a normal second copy of the gene. However, women are not just carriers and they can have Fabry related health problems. Fabry disease is unique, as most X-linked disorders affect males primarily. It is important to speak to your physician about all your signs and symptoms and not rule out Fabry disease if you are a female.
The chance for children to have Fabry disease depends on whether the father or the mother has Fabry disease and the X-chromosome with the non-working GLA gene. If a man's X-chromosome contains the nonworking GLA gene, he will pass it on to all of his daughters and none of his sons. If one of a women's X-chromosomes contains the nonworking GLA gene, she will have a 50% chance with each pregnancy of passing it on to both her daughters and sons. Both males and females can have Fabry disease.
To find a genetic professional near you who can discuss the chance for someone with Fabry disease to have a child with Fabry disease or discuss genetic testing options consult a genetic counselor. Genetic counselors can be found on the National Society of Genetic Counselors website: http://www.aboutgeneticcounselors.com/
Laney, D., Bennett R.L., Clarke V., Fox, A., Hopkin, J., Johnson, J., et al. (2013). Fabry Disease Practice Guidelines: Recommendations of the National Society of Genetic Counselors. Journal of Genetic Counseling, 22, 555-564.
National Fabry Disease Foundation. (n.d.). Retrieved from http://www.fabrydisease.org.