What happens to children that get tay-sachs disease

Tay-sachs disease is a disease that attacks the brain and essentially what happens is in your DNA, there is a code for making a protein that dissolves excess fat in your brain. If the code if wrong, the protein can't complete the task of dissolving that fat so the fat builds up in the brain to the point where it crushes vital brain cells which can lead to blindness, loss of motor skills, and leaves a window from around 6 - 8 years old for the child.

it's filtration, but this is an assumption so my apologies if i got this