Fabry disease is an inherited condition, which means that it runs in families. You might carry the mutated gene for this disease and not know it because it can take 10 years or more to get a diagnosis, even after you have symptoms.
Gene tests can let you know whether you have Fabry disease early, before it affects your heart, kidneys, or other organs. Once you find out that you have the abnormal gene, you can begin treatment to prevent these problems. You can also let other members of your family know that they might have Fabry disease so they can get tested too.
How People Inherit Fabry Disease
A mutation (change) in the GLA gene causes Fabry disease. This gene carries the instructions to make an enzyme called "alpha-galactosidase A" that breaks down a type of fat in your body.
When the GLA gene doesn't work right, your body doesn't make the enzyme and fat builds up in cells all over your body. The fat buildup can cause problems like kidney damage, heart attack, or stroke.
The faulty gene is on the X chromosome. Girls and women have two X chromosomes (XX). Boys and men have one X and one Y chromosome (XY).
Women may not show symptoms because their other X chromosome is normal, so they're still able to make the alpha-galactosidase A enzyme. Because men only have one X chromosome, they make little to none of this enzyme, so they will have symptoms of the disease.
Who Should Get Tested?
Ask your doctor whether you need a gene test if you have family members with Fabry disease. You may also need to get tested if you have symptoms like these:
- Burning or hot pain in your hands and feet
- Reddish-purple spots on your skin, especially in the area that your bathing suit covers
- Less sweating than normal
- Cloudiness or streaks in the front part of your eye
- Ringing in your ears
- Hearing loss
Insurance usually covers the cost of genetic testing for Fabry disease. The American Association of Kidney Patients also covers the cost through its Free Fabry Diagnostic Testing and Education Program.
How Genetic Testing Works
Doctors use a test that measures the amount of alpha-galactosidase A enzyme in your blood. Boys and men with Fabry disease have none of this enzyme or very little of it. Some may also need genetic testing for the abnormal gene.
Because girls and women can have almost normal levels of the enzyme, they'll need genetic test to confirm that they have the abnormal gene that causes Fabry disease. Many women with the abnormal gene can get symptoms in some parts of their body. They can also pass along an abnormal gene to their children.
Doctors can test for Fabry disease before a baby is born. They remove a sample of fluid or tissue from around the growing baby and test it for the enzyme. A few states, including Washington and Illinois, routinely screen newborns for Fabry disease.
After one person in your family gets a diagnosis of Fabry disease, your doctor can make a family tree. Then other family members can get tested to see if they also carry the gene. When one person in a family has this disease, an average of five more family members are also diagnosed, research finds.
Once your family members learn that they have Fabry disease, they can get started on treatment if they need it.
A genetic counselor can help you learn whether you're at risk for Fabry disease or if you could pass the gene to your children. If you've already had a genetic test, the counselor can discuss your results with you and tell you what they mean.
Genetic counseling can also help you learn about options if you want to have children. A test called preimplantation genetic diagnosis (PGT) is available for those who have Fabry disease in their family. To start, you'd have in vitro fertilization (IVF) to make a few embryos. PGT then tests each embryo before the doctor places them into the mother's uterus. This method lets you choose embryos without the Fabry disease gene.
You can ask your primary care doctor to refer you to a genetic counselor, or contact your insurance company to find a counselor who is part of your health care plan. The National Society of Genetic Counselors also has a directory on its web site of genetic counselors around the country.