Tay-Sachs disease is a progressive neurological disorder that typically manifests after six months of normal development in infants. Initially, a regression in social interactions, such as smiling, and motor skills like sitting, crawling, and walking is noticed. As the disease progresses, severe symptoms emerge, including muscle weakness, coordination problems, seizures, progressive blindness and deafness, and difficulties with swallowing and breathing. A characteristic and definitive finding upon examination is the "cherry-red spot" appearance in the macula of the retina. This spot can eventually lead to vision loss and complete blindness. With the worsening of symptoms and the development of dementia, patients become bedridden and typically pass away before the age of 5, usually around 3 years old. In Tay-Sachs disease, ganglioside accumulation is observed in the gray matter of the brain.

The main symptoms observed include:
* Regression in mental and social skills (e.g., smiling)
* Abnormal startle reflexes
* Motor coordination disorder
* Epileptic seizures
* Inability to sit unsupported, crawl, or walk
* Progressive muscle weakness and paralysis
* Growth retardation
* Blindness and deafness
* Dementia
* Difficulty breathing and swallowing