Neuropsychiatric aspects of adult-onset Tay-Sachs disease: two case reports with several new findings.

Deficiency of hexosaminidase A causes the GM2 gangliosidosis known as Tay-Sachs disease. It is now known that this condition has several late-onset variants that cause numerous neuropsychiatric disturbances. Early recognition is important because treatment with phenothiazines and heterocyclic antidepressants may worsen the course. The authors report two cases with several new findings, including prominent psychiatric symptoms without psychosis early in the course of the illness.