The symptoms of Tay-Sachs diseases usually begin to appear once a child is six months old (Nash, "Tay-Sachs disease"). As the disease progresses, the severity of the symptoms increases.

These are slowing down developments (
  • muscle weaken
  • loss of skills including
    • turning over
    • sitting
    • crawling
  • Seizures
  • loss of vision
  • loss of hearing
  • inability to swallow
  • mental retardation
  • paralysis
  • dementia