Fabry Disease Management and Outlook

Fabry disease is a rare inherited disorder that causes a specific type of fat, globotriaosylceramide, to accumulate in the cells. Symptoms range from mild to life-threatening, depending on the age that they begin. About one in 40,000 to 60,000 males have Fabry disease. Females get it, too, but the prevalence is unknown.

Alpha-GAL

Fabry disease results from a deficiency of alpha-GAL, an enzyme that prevents fat-like substances from accumulating in the blood vessels and tissues throughout the body. This disease primarily affects the brain, central nervous system, heart, kidneys, and skin. Symptoms can develop in children and adults, though experts believe mild late-onset forms of the disease are more common than severe forms.

Types of Fabry Disease

There are two types of Fabry disease. The classic type has symptoms that appear in childhood or teenagehood. The hallmark symptom of this form, a burning sensation in the hands and feet, starts as young as 2 and gets worse over time. Late-onset Fabry disease is when people do not have symptoms until they are in their 30s or older; heart disease or kidney failure may be the first indication of a problem.

Symptoms

Symptoms of Fabry disease include pain in the hands and feet, clusters of dark red spots on the skin, cloudiness in the cornea, hearing loss, and an inability to sweat. When the internal organs are affected, the fatty accumulations can lead to heart attacks, strokes, and kidney damage. Late-onset Fabry disease usually only affects the kidneys and heart.

Genetics

Fabry disease is linked to the X chromosome, which can explain how the condition is passed down in families. Males who inherit the gene will develop Fabry disease as they only have one X chromosome, and, therefore, only a defective copy of the gene. Females have two X chromosomes and may inherit a working copy of the gene from their other parent; however, even one defective gene can cause mild to severe symptoms in females. A woman with Fabry disease has a 50/50 chance of passing it on to her children, while a man will pass it on to his daughters through their second X chromosome but not to his sons.

Diagnosis

Fabry disease is diagnosed through various lab tests. The most accurate diagnostic test measures the alpha-GAL enzyme in the blood, but it is most reliable in males. Enzyme testing for Fabry disease is included in newborn screenings in some states. Genetic testing is also valuable, especially for females, as it can identify the gene mutation responsible for the disease.

Enzyme Replacement Therapy

One promising treatment is enzyme replacement therapy. Patients receive an IV infusion of synthetic replacement enzymes to do the job of alpha-GAL and prevent fatty buildup. It is not a cure, but it slows the accumulation of fatty substances, preventing or slowing the development of damage to the heart and kidneys.

Oral Chaperone Therapy

Oral chaperone therapy treats Fabry disease by introducing a small molecule that repairs the defective alpha-GAL enzymes, enabling them to break down the fatty substance and prevent damage. This treatment is very convenient as it is in pill form, but it only works for certain mutations and patients.

ACE Inhibitors

ACE inhibitors are another common treatment for the symptoms of Fabry disease. These drugs can help prolong kidney function by reducing the amount of protein in the urine, hopefully preventing the need for dialysis or a kidney transplant. Interestingly, if a person with Fabry disease receives a kidney transplant, the transplanted organ is not affected by the disease, and kidney function will return to normal.

Management

People with Fabry disease require frequent monitoring and follow-ups. Doctors’ visits should be done at least once a year, and heart and kidney function are closely monitored. Management usually includes brain scans every two years and annual hearing checks. People with Fabry disease see multiple doctors, including heart, kidney, and eye specialists, and should seek out professionals familiar with the disease.

Prognosis

Fabry disease is a progressive disease with no cure. As people with this disease grow older, symptoms and complications worsen. Males with this condition tend to live into their 50s, while women can live into their 70s. Maintaining heart and kidney function and reducing stroke risks are key to living as long as possible.