What is one of the primary symptoms of Tay-Sachs disease?

One of the primary symptoms of Tay-Sachs disease is the presence of a cherry red spot on each retina. This characteristic finding is a result of the accumulation of GM2 gangliosides in the retinal ganglion cells, which leads to the degeneration of these cells. The cherry red spot becomes visible during an ophthalmological examination and is a hallmark sign of the disease. This symptom typically appears in infants who are affected by Tay-Sachs, and it is indicative of the underlying pathology associated with the disorder.

In Tay-Sachs disease, this specific retinal sign can help in diagnosing the condition, particularly when combined with other clinical findings. The other symptoms, like muscle weakness and developmental delays, may occur as the disease progresses, but the cherry red spot is one of the key features that specifically associates with Tay-Sachs at the ophthalmological level.