• Overview
• Inheritance
• Symptoms
  • The Kidney
  • The Brain and Nerves
  • The Heart
  • The Eyes
  • The Skin
  • The Digestive Tract
• Testing
• Treatment
• Resources

Fabry disease is inherited in an X-linked recessive pattern and affects mostly males. The a-galactosidase A gene is located on one of the sex chromosomes, called the X chromosome. Females have two X chromosomes in each cell, and males have one X chromosome and one Y chromosome in each cell. If a male's a-galactosidase A gene has a mutation (a change in a gene which causes it to work incorrectly), then he has Fabry disease.

If one copy of a female's a-galactosidase A gene has a mutation, she is a Fabry carrier. Because their other a-galactosidase A gene copy functions normally, carriers usually do not have severe Fabry disease. However, some Fabry carriers have some symptoms of the disease. For example, about 70%-90% of Fabry carriers have the characteristic eye symptoms. Rarely, carriers may have a severe form of the disease, as seen in affected males.

Female blood relatives (sisters, aunts, cousins, etc.) of patients with Fabry disease may be carriers of a Fabry gene mutation. Females with no family history of Fabry disease may also be carriers.

Sons of carrier mothers will have Fabry disease if they inherit the X chromosome containing the a-galactosidase A mutation. When the mother is a Fabry carrier, and the father does not have Fabry disease, then in each and every pregnancy, there is: a 25% chance of having a daughter who is a carrier, a 25% chance of having a daughter who is not a carrier, a 25% chance of having a son without Fabry disease, and a 25% chance of having a son with Fabry disease.

All daughters of males who have Fabry disease will be carriers. All sons of males who have Fabry disease will be unaffected.

The different details of each family history will cause the risk figures and other genetic counseling issues to vary from family to family. The specific information for YOUR family will be covered during the genetic counseling consultation part of your evaluation at the Center.