Tay-Sachs disease (also known as GM2 gangliosidosis or hexosaminidase A deficiency) is an autosomal recessive genetic disorder. In its most common variant (known as infantile Tay-Sachs disease), it causes a progressive deterioration of mental and physical abilities that commences around six months of age and usually results in death by the age of four. 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 cure or treatment.
Contributions by Metzenberg, Jfdwolff, and JDG.