Why is an important enzyme missing in patients with Tay-Sachs Disease?
We all carry genes – many of them. Most of our genes instruct our cells to perform normal useful tasks such as producing essential enzymes. We each carry two copies of each of our genes. We also carry mutations. Mutations are altered genetic instructions. Many mutations are helpful and allow us to better adapt to our world. Some mutations, however, are harmful. We all carry at least one or two harmful mutations. One such mutation which is harmful when inherited from both parents can cause Tay-Sachs disease. In most cases, we are protected from harmful effects of mutant genes such as Tay-Sachs disease genes because we also carry a copy of the normal gene.
