Tay-Sachs Disease — RACP Paediatrics MCQ

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HardGenetics & MetabolicTay-Sachs DiseaseRACP Paediatrics

A 2-year-old boy has global developmental delay, seizures, and a cherry-red spot on fundoscopy. There is no hepatosplenomegaly. Hexosaminidase A activity is deficient. What is the diagnosis?

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Correct answer: A — Tay-Sachs disease

Tay-Sachs disease: hexosaminidase A deficiency causing GM2 ganglioside accumulation. Cherry-red spot (without hepatosplenomegaly, unlike Niemann-Pick A), progressive neurodegeneration, hyperacusis (exaggerated startle response), and macrocephaly. Autosomal recessive, common in Ashkenazi Jewish populations.

Reference: RACP – 2024 – Paediatric Curriculum: Metabolic Medicine