Storage of GM(2)ganglioside begins during pregnancy. However, the baby usually develops normally until about six months of age. The nervous system becomes progressively affected and sadly the disease is usually fatal between age three to five years. The child becomes blind, deaf and unable to swallow. Muscles begin to waste and paralysis develops. Additionally, epileptic seizures may occur.
Late-onset Tay Sachs disease (LOTS) is much less common than the classical infant form. Individuals with LOTS have very reduced enzyme levels rather than complete absence.
Onset of LOTS is later and individuals vary in the way it affects them.