What is a common symptom of acute infantile Tay-Sachs disease?

In the context of acute infantile Tay-Sachs disease, the exaggerated startle response is a hallmark symptom that can help distinguish this condition. This exaggerated response, also known as the "startle reflex," occurs because of the neural degeneration associated with the disease, which affects the central nervous system. Infants may react more intensely to stimuli that would not provoke such a reaction in healthy infants.

Tay-Sachs disease is known for its impact on neurological development, resulting in various symptoms as the condition progresses. The exaggerated startle response is often one of the first noticeable signs of the disorder, typically appearing between 3 and 6 months of age.

Other symptoms associated with Tay-Sachs include loss of muscle strength and progressive macrocephaly (increase in head size), as well as a cherry red spot on the retina. While these manifestations are also seen in Tay-Sachs disease, the pivotal characteristic of the exaggerated startle response in infants specifically points to the acute form of this genetic condition.