This enzyme plays a crucial role in the breakdown of a fatty substance called GM2 ganglioside. GM2 ganglioside is a complex lipid found in brain cells.
Here's how it works:
1. Normal function of HEXA: The enzyme hexosaminidase A breaks down GM2 ganglioside into simpler molecules that can be further processed and used by the body.
2. Consequences of a faulty HEXA: When the HEXA gene is mutated, the enzyme hexosaminidase A is either missing or doesn't function properly. This leads to a build-up of GM2 ganglioside in brain cells, particularly in nerve cells.
The accumulation of GM2 ganglioside in the brain disrupts the normal function of neurons, leading to the devastating symptoms of Tay-Sachs disease. These symptoms include:
* Progressive neurological deterioration: This includes loss of motor skills, seizures, blindness, and deafness.
* Mental impairment: Cognitive decline and developmental delays.
* Cherry red spot: A characteristic feature observed in the retina, due to the accumulation of GM2 ganglioside.
In essence, the HEXA gene normally ensures the proper breakdown of GM2 ganglioside in brain cells. A defective HEXA gene disrupts this process, causing a build-up of GM2 ganglioside and leading to the devastating consequences of Tay-Sachs disease.
