Tay-Sachs is a disease where your lysosomes aren’t working right. It’s a disease you get in your DNA from your parents. Both your mother and your father have to have the disease in their DNA in order for you to get it. It is not catching.
One of the things your lysosomes do is to use enzymes to break down extra stuff in your body and recycle it. To recycle lipids, or fatty acids, your lysosomes need an enzyme called hexosaminidase A, or hex A for short. People with Tay-Sachs don’t have the DNA instructions to make Hex-A correctly. Usually they make Hex-A, but something is wrong with the hooks that the cell uses to move the Hex-A around inside the cell.
When they’re first born, babies with Tay-Sachs are fine. But around the time they are eight months old, these babies get to have too much lipids in the lysosomes of their brain cells, and the lipids start to hurt their brains. There isn’t any cure for Tay-Sachs disease yet. Pretty much everyone who gets Tay-Sachs as a baby dies by the time they are five years old.
One good reason for scientists to try to understand how lysosomes work better is so that they could figure out how to cure Tay-Sachs disease.