causes gauchers disease (type 1), a progressive genetic disease due to an enzyme defect. The enzyme, glucocerebrosidase, is needed to break down the chemical glucocerebroside. The enzyme defect in persons with gauchers disease (GD) leads to the accumulation of glucocerebroside in the spleen, liver, and lymph nodes. The most common early sign is enlargement of the spleen (located in the upper left abdomen). Other signs include low red blood cell counts (anaemia), a decrease in blood clotting cells (platelets), increased pigmentation of the skin, and a yellow fatty spot on the white of the eye (a pinguecula). Severe bone involvement can lead to pain and collapse of the bone of the hips, shoulders, and spine. The GD gene is on chromosome 1. The disease is a recessive trait. Both parents carry a GD gene and transmit it for their child with the disease. The parents risk of a child with the disease is 1 in 4 with each pregnancy. This type of gauchers disease (noncerebral juvenile gauchers disease) is most common in Ashkenazi jews (of European origin) and is the most common genetic disease among jews in the united states.