Inheritance of Fabry DiseaseNext Topic
All cells in the human body except for sperm and egg cells have 23 pairs of chromosomes. Chromosomes are made up of DNA, and contain thousands of genes which determine not only all of our physical characteristics such as height, eye, hair, or skin color, but also how well our bodies function. The first 22 pairs are numbered and called autosomes, while the 23rd pair contains the sex chromosomes. Females have two X chromosomes, and males have an X and a Y chromosome. During the process of making sperm and egg cells, one member of each pair is donated to a single sperm or egg cell for a total of 23 individual chromosomes. The chromosome pairs come together again at fertilization when sperm and egg cells unite and offspring receive half of their genetic material, or one member of each pair of chromosomes from their mother, and the other member of each pair from their father.
Fabry disease is an "X-linked" inherited disorder because the genetic alteration (or mutation) is found in the alpha-galactosidase A gene which is located on the X chromosome. X-linked diseases are passed on to daughters and sons differently depending on whether the father is affected (Example 1 below) or the mother is affected (Example 2 below).
An affected male (XY) will pass the altered gene to all of his daughters but none of his sons.
Example of the inheritance of Fabry disease from an affected male.
An affected female (XX) will have a 50% chance of passing the altered gene to any child she has, whether they are male or female.
Example of the inheritance of Fabry disease from an affected female.
Females with Fabry disease may often be referred to as 'carriers' because they have one normal X chromosome and one altered X chromosome. However, it is important to remember that females with Fabry disease have an extremely variable presentation and may be as severely affected as males, more mildly affected, or not affected at all.
For more information on how Fabry disease affects women, please see the Women and Fabry fact sheet.
Family History
Many health problems have a genetic link, which means that the level of risk associated with a particular disease or health condition is inherited through our parents. Fabry disease is one such condition.
If Fabry disease has been identified within your family, taking a look at your family's medical history can illustrate who has been affected as well as who is likely to be affected now and in the future. A family tree is also a useful tool for discussing Fabry disease with other family members, your family doctor or your specialist.
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