How is Sandhoff disease different from Tay-Sachs?

Tay-Sachs Disease:

- Caused by mutations in the HEXA gene, leading to a deficient enzyme called Hexosaminidase A.

- Primarily affects the nervous system and leads to a progressive deterioration of cognitive and physical abilities.

- Specific to Ashkenazi Jewish descendants and populations where consanguineous marriages are more prevalent.

- Characterized by the accumulation of a fatty substance called GM2 ganglioside in the brain and other nerve cells.

Sandhoff Disease:

- Caused by mutations in the HEXB gene, resulting in a deficient enzyme called Hexosaminidase B.

- Similar to Tay-Sachs, it affects the nervous system and causes neurodegeneration.

- It is considered a pan-ethnic disorder and is not limited to any particular population or ethnic background.

- It also involves the accumulation of GM2 ganglioside, but the storage occurs both within the lysosomes and the cytoplasm of neurons.

In essence, both Tay-Sachs and Sandhoff diseases belong to a broader group of genetic conditions known as GM2 gangliosidoses, but they differ in the specific genes affected, the populations in which they are more prevalent, and the extent of GM2 ganglioside storage.