If one person in a family has Fabry disease, other family members (including siblings, children, parents, aunts, uncles, and cousins) may also have Fabry disease. On average, five other family members are likely to be affected as well. This makes Fabry disease very much a family disease—not just immediate family, but extended family as well.
The inheritance pattern is important because many patients suffering from Fabry disease endure many years of unmanaged symptoms and misdiagnoses. Tracing Fabry disease within a family accelerates the time to an accurate diagnosis.
Fabry disease is an X-linked disease, which means that the altered gene is located on the X chromosome. To understand this better, it is helpful to understand a little about genetics.
Chromosomes are the packaged genetic information used to make proteins that allow your body to work. Humans have 46 chromosomes. Two of them, called sex chromosomes, or X and Y chromosomes, determine whether a person will be male or female. Females have two X chromosomes, and males have an X and a Y chromosome. Females inherit an X chromosome from both their mother and father. Males inherit their X chromosome from their mother and their Y chromosome from their father.
The gene associated with Fabry disease is called GLA, and it is located on the X chromosome. The chance of inheriting the GLA alteration for Fabry disease depends on whether it came from the father or the mother. For each pregnancy, a woman with Fabry disease has a 50% chance (1 in 2) of passing on the GLA alteration to her son or daughter.
However, a father with Fabry disease will always pass on the GLA alteration to his daughter. On the other hand, the father will never pass on the GLA alteration to any of his sons, since sons always get their X chromosome from their mother.
Both males and females can be affected by Fabry disease as both sexes have at least one X chromosome.
This chart illustrates the inheritance pattern.
The first step in tracing Fabry disease in your family is creating a Medical Family Tree. A Medical Family Tree can help you understand the inheritance pattern in your family and the risk of passing on Fabry disease. A geneticist, genetic counselor, or CareConnectPSS Patient Education Liaison (PEL) can help you create a Medical Family Tree and facilitate a family discussion.
Here is an example of a Medical Family Tree:
If you have been diagnosed with Fabry disease, there are several important reasons why you may want to consider discussing it with your immediate and extended family:
When and how to share your diagnosis is something you may wish to discuss with your treating physician or a CareConnectPSS Patient Education Liaison.
Testing enables earlier diagnosis and earlier access to appropriate care. A negative test result can relieve uncertainty, while a positive result can allow for informed health choices going forward.
When you are caring for someone with Fabry disease, it is important to take care of yourself both physically and mentally. Be sure to tap into CareConnectPSS, which offers free personalized and confidential support services for both patients with Fabry disease and those caring for them.