A 6-month-old baby boy has progressive liver enlargement, generalised hypotonia, macroglossia, and an echocardiogram showing severe hypertrophic cardiomyopathy. Enzyme assay reveals absent acid alpha-glucosidase (GAA) activity. What is the diagnosis?

• A Gaucher disease type 2
• B Pompe disease (glycogen storage disease type II) ✓
• C Niemann-Pick type A
• D Fabry disease

Explanation

Pompe disease (GSD type II) is caused by deficiency of lysosomal acid alpha-glucosidase (GAA), leading to glycogen accumulation in lysosomes of all tissues, especially cardiac and skeletal muscle. The classic infantile form presents with severe hypertrophic cardiomyopathy, profound hypotonia ('floppy infant'), macroglossia, and hepatomegaly within the first 6 months, with rapidly progressive cardiorespiratory failure. Diagnosis is confirmed by enzyme assay (dried blood spot or leukocytes). Enzyme replacement therapy (alglucosidase alfa) has dramatically improved prognosis. Gaucher type 2 affects the CNS. Niemann-Pick A has hepatosplenomegaly and neurodegeneration but not cardiomyopathy. Fabry disease presents in adult males with neuropathic pain and renal/cardiac involvement.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.