A 17-month-old boy is being evaluated for neurologic regression. He had a normal neonatal course and early development until age 5 months. The boy subsequently experienced gradual regression of developmental milestones, and now has inability to sit with support, poor head control, and loss of a social smile. Weight and height are below the 5^th percentile. Physical examination shows an enlarged liver and spleen, diminished deep tendon reflexes in all limbs, and hypotonia. Funduscopic reveals cherry-red macular spot. This patient most likely has an accumulation of which of the following substrates?

Question

Quizplus · Accepted Answer

Eductional Objective: In Niemann-Pick disease, sphingomyelinase deficiency causes accumulation of the lipid sphingomyelin.  Clinical features include hepatosplenomegaly, neurologic regression, and a cherry-red macular spot in infancy.

A 17-Month-Old Boy Is Being Evaluated for Neurologic Regression