Tay-Sachs disease

Definition:

A familial disorder found in east European Jewish families, which results in early death.

Causes, incidence, and risk factors:

Tay-Sachs disease is caused by an deficiency of hexosaminidase, an exzyme that is important in the metabolism of gangliosides (a fatty acid). These fatty acids then accumulate in the brain causing neurological deterioration. Tay-Sachs disease is inherited as a recessive gene.

Symptoms begin to appear at 3 to 6 months old. Symptoms progress rapidly, and the child usually dies before 3 years old. Risk factors include having a Ashkenazi Jewish background. In this group, the incidence is 1 out of 2,500 people.