A Jewish couple of Eastern European descent presents to the clinic for prena-
tal counseling after their only child died early in childhood. The family could
not remember the name of the disorder but said it was common in their ances-
try. Their first child was normal at birth, a slightly larger than normal head cir-
cumference, an abnormal “eye finding,” and a severe progressive neurologic
disease with decreased motor skills and eventually death. The autopsy is con-
sistent with Tay-Sachs disease.
What type of inheritance is this disorder?
What is the biochemical cause of the disorder?