According to WebMD, Tay Sachs disease is an autosomal recessive disease, meaning both parents need to have a copy of the mutated gene in order to pass it onto their offspring. Tay Sachs disease is a very rare genetic disorder, usually affecting those of Ashkenazi Jewish heritage.
Tay Sachs disease gradually destroys nerve cells in the brain and spinal cord, according to the National Library of Medicine. As more neurons are destroyed, motor functions are affected and eventually deteriorate entirely in the form of paralysis. Intellectual development is also stunted. The most common form of this disease begins to affect children as young as 3 to 6 months of age.