Fabry Disease
(Fabry's Disease; Angiokeratoma Corporis Diffusum)
-
Fabry disease occurs when the body lacks enzymes needed to break down a glycolipid.
-
Symptoms include skin growths, eye problems, kidney failure, and heart disease.
-
The diagnosis is based on the results of prenatal screening tests, newborn screening tests, and other blood tests.
-
Most children who have Fabry disease live to adulthood.
-
Treatment includes enzyme replacement therapy.
(See also Overview of Hereditary Metabolic Disorders.)
Sphingolipidoses occur when people do not have the enzymes needed to break down (metabolize) sphingolipids, which are compounds that protect the cell surface and serve certain functions in the cells. There are many types of sphingolipidoses besides Fabry disease:
-
Gaucher disease (most common)
-
Niemann-Pick disease (types A and B)
In Fabry disease, a glycolipid, which is a product of fat metabolism, accumulates in tissues. The enzyme needed to breakdown the glycolipid, called alpha-galactosidase A, does not work correctly. Because the defective gene for this rare inherited disorder is carried on the X chromosome, the full-blown disease occurs only in boys (see X-Linked Inheritance). Because girls have two X chromosomes, affected girls may have symptoms but do not develop full-blown Fabry disease.
The accumulation of glycolipid causes noncancerous (benign) skin growths (angiokeratomas) to form on the lower part of the trunk. The corneas become cloudy, resulting in poor vision. A burning pain may develop in the arms and legs, and children may have episodes of fever. Children with Fabry disease eventually develop kidney failure and heart disease, although, most often, they live into adulthood. Kidney failure may lead to high blood pressure, which may result in stroke.
Diagnosis
Before birth, Fabry disease can be diagnosed in the fetus by using the prenatal screening tests chorionic villus sampling or amniocentesis.
After birth, Fabry disease may be diagnosed in some states by routine newborn screening tests. Doctors measure levels of alpha-galactosidase A in blood or in white blood cells.
Treatment
Doctors treat Fabry disease with enzyme replacement therapy (agalsidase beta). Treatment also consists of taking analgesics to help relieve pain and fever or antiseizure drugs.
People with kidney failure may need a kidney transplant.
