Fabry disease: A genetic disease caused by a mutation in the GLA gene, resulting in a deficiency of the enzyme alpha-galactosidase A, also known as ceramide trihexosidase. This enzyme is essential to the metabolism of a fat compound known as globotriaosylceramide. Without alpha-galactosidase A, this fatty substance accumulates in the walls of blood vessels, leading to narrowing and decreased blood flow to the tissues normally supplied by these vessels. Small vessels in the skin, kidneys, heart, and nervous system are preferentially affected, impairing function of these organs. Males with Fabry disease are more severely affected than females with it because the gene for Fabry disease is on the X chromosome. Males have only one X, whereas females have a second X and therefore some enzyme activity. Females with partial enzyme activity may not show any symptoms, or may have symptoms as severe as affected males. Diagnosis is made by determining the level of alpha-galactosidase A in blood plasma or through genetic testing. Symptoms may include blood vessel-filled skin lesions known as angiokeratomas over the hips, buttocks, thighs, and lower belly with fever accompanying attacks of pain in the fingers and toes. Potentially life-threatening complications such as stroke, heart failure, and kidney 'failure may also occur. Treatment includes intravenously-administered enzyme replacement therapy with agalsidase beta (brand name: Fabrazyme), which reduces the fat accumulation in many types of cells and tissues. Episodes of pain in the hands and feet may benefit from certain medications. Also known as Anderson-Fabry disease and angiokeratoma corporis diffusum universale.