Tay-Sachs disease (aka GM2 gangliosidosis or hexosaminidase A deficiency) is a rare autosomal recessive genetic disorder. In its most common variant (infantile Tay-Sachs disease), it causes a progressive deterioration of nerve cells and of mental and physical abilities that begins around 7mo and usually results in death by the age of 4yo. The disease occurs when harmful quantities of cell membrane components known as gangliosides accumulate in the brain's nerve cells, eventually leading to the premature death of the cells. A ganglioside is a form of sphingolipid, which makes Tay-Sachs disease a member of the sphingolipidoses. There is no known Tx.