Fabry disease is a genetic disease passed down from parents to children. To better understand how Fabry disease is inherited, and who may be affected in the family, a basic understanding of genetics and inheritance is helpful.

Genetics

All of our hereditary information is contained on genes. We have genes that determine our physical characteristics like our hair color, eye color, height, etc. We also have genes that are responsible for specific functions such as our metabolism and growth.

All of our thousands of genes are contained on chromosomes. Each human cell contains 46 chromosomes (23 pairs). We inherit 23 chromosomes from our mother and 23 from our father for a total of 46 chromosomes. Two of the 46 chromosomes (or one pair) are called the sex chromosomes and are referred to as either an X or a Y chromosome. Women have two X chromosomes (XX) and men have one X chromosome and one Y chromosome (XY). Since women only have X chromosomes (XX), they will always pass an X chromosome to their children. On the other hand, men can pass an X or a Y chromosome to their child. If a man passes the X chromosome to his child, the child will be female. If a Y chromosome is passed on, the child will be male. It is completely random whether a man will pass an X or Y chromosome to his child.

The X and Y chromosomes are called sex chromosomes because most of the genes located on them are involved with determining a person's sex and sexual function. What may be confusing is that, while some genes on the X chromosome are responsible for sexual function and fertility, there are also other genes located on this chromosome that have nothing to do with sex. For example, the gene that helps our blood to clot and the gene that allows us to see color are located on the X chromosome. Likewise, the gene that makes alpha-GAL is located on the X chromosome. In patients with Fabry disease, this gene does not function properly and the body does not make sufficient quantities of alpha-GAL.

Click here for more information on Inheritance of Fabry Disease and Tracing Fabry Disease.