Fabry disease, sometimes called Anderson-Fabry disease, is a genetic disorder in which cell structures, called lysosomes, metabolize fatty molecules poorly or not at all. When this happens the cell fills up with unused fatty molecules, impairing cellular function. The accumulation eventually narrows blood vessels and harms vital organs, leading to the symptoms of Fabry disease.
Definition & Facts
Fabry disease is a rare condition affecting many parts of the body. The eyes, skin, gastrointestinal tract, heart, brain, and nervous system are compromised by the deficiency of an enzyme called alpha-galactosidase A. Because of fatty substance build-up in vessels and tissues, Fabry disease may be described as a lysosomal storage disorder.
If one member of a family is diagnosed with this disease, others may have it too, and the disease is far more common in males than in females. It is suspected that one in 40,000 males may be affected, and their life expectancy is approximately 58 years. Life expectancy for females is 75 years.
Symptoms & Complaints
- Small red spots on the body below the belly button and above the knees. These skin lesions are called angiokeritoma, and are not painful.
- Ringing in the ears (tinnitus) or hearing loss.
- Blurred vision or cloudy vision and white spots, or opacities, on the cornea. Blood vessels there may be very dilated.
- Inability or low ability to sweat, combined with fever in hot weather or when fatigued. Hands and feet may burn.
- Stomach pain and bowel movement directly after a meal.
Eventually individuals are at risk for heart attack or stroke. The classic symptoms of circulatory disease manifest themselves with high blood pressure (hypertension), enlarged heart cardiomegaly, kidney failure, and heart failure. These symptoms or demise from circulatory failure early in life is reason for Fabry disease concern.
Fabry disease is caused by an X-linked genetic mutation. Males have an X and Y chromosome, so one mutated gene on the X chromosome will cause the condition. Females have two X chromosomes, so an altered genetic copy of the gene on one X chromosome usually results in disease of less severity or no symptoms at all. Due to the heritable causes of Fabry disease, genetic counseling may be sought which involves compiling a document with the health status of several generations of relatives if the information is available.
Diagnosis & Tests
A diagnosis of Fabry disease early in life delivers the best prognosis for treatment. Prenatal diagnosis is available if a parent or relative has Fabry disease. The prenatal diagnosis is made by measuring the alpha-galactosidase A activity in the fluid surrounding the fetus or from tissue removed from the fetus. Advice to parents from specialists in Fabry disease is available with the testing.
A combination of the many manifestations of Fabry disease may cause a doctor to suspect the condition in a child or adult, especially the small, red spots called angiokeratoma. Then an individual will be referred to a center specializing in the testing and diagnosis of the disorder and proper treatment.
A male or female suspected to have Fabry disease can receive a diagnosis via laboratory testing of a blood sample determining alpha-GAL enzyme activity (alpha-galactosidase A) in the blood. A more effective diagnosis for females involves a laboratory genetic test with DNA analysis. This will confirm diagnosis if there is a family history of Fabry disease.
Treatment & Therapy
Fabry disease is not curable. Instead, the condition is managed with replacement of the missing alpha-GAL A enzyme. A drug called Fabrazyme is a specific treatment for Fabry disease, called ERT, or enzyme replacement therapy. The treatment lowers a substance called globotriaosylceramide (GL-3) which lines vessels of cells and the kidneys. This drug is administered through infusion, and its safety for those with possible allergic reactions or for those younger than eight years old has not been determined.
Physician experts in Fabry disease now recommend initiation of ERT be started as soon as possible for appropriate candidates. Studies confirmed that ERT improved heart function, stabilized kidney function and improved quality of life. Other treatments focus upon relieving symptoms. They include:
- Medications such as gabapentin for relief of pain and burning.
- Antiplatelet drugs such as aspirin to prevent stroke.
- Warfarin to prevent blood clots in the heart.
- Drugs to relieve gastrointestinal symptoms.
- ACE inhibitors to relieve high kidney protein due to renal damage.
- Hearing aids for hearing loss.
- Hypertensive drugs for high blood pressure and high cholesterol drugs.
Prevention & Prophylaxis
Patients are advised not to smoke and to follow a balanced diet and regular exercise program. The exercise program may be modified due to disease manifestations such as pain upon exertion or overheating. With progression of the disease, blood dialysis and possible kidney transplantation is an option.