Advanced Dental Admission Test (ADAT)

What deficiency is associated with Tay-Sachs disease?

1. Hexosaminidase B deficiency

2. Hexosaminidase A deficiency

3. Galactocerebrosidase deficiency

4. Alpha galactosidase deficiency

The correct answer is: Hexosaminidase A deficiency

Tay-Sachs disease is a genetic disorder that results from a deficiency in hexosaminidase A, an enzyme critical for the metabolism of certain lipids in the body, specifically GM2 gangliosides. When hexosaminidase A is deficient, GM2 gangliosides accumulate in the nerve cells, leading to progressive neurological damage and other severe symptoms related to the central nervous system. The primary deficiency in Tay-Sachs allows for this buildup, causing the characteristic clinical manifestations of the disease, which include motor and cognitive decline, loss of coordination, and developmental regression. Understanding the role of hexosaminidase A is essential for recognizing the biochemical mechanisms behind Tay-Sachs and for distinguishing it from other lysosomal storage disorders caused by different enzyme deficiencies.