PRKAG2 Syndrome — EECC MCQ

Instant feedback + full explanation. One question, done properly.

HardCardiomyopathyPRKAG2 SyndromeEECC

A 35-year-old man presents with unexplained LVH (wall thickness 15 mm), short PR interval (100 ms), and WPW pattern on ECG. He has progressive exercise intolerance. His CK is mildly elevated. Genetic testing reveals a PRKAG2 mutation. What is the diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — PRKAG2 syndrome — a glycogen storage cardiomyopathy mimicking HCM, associated with progressive conduction disease, pre-excitation, and risk of heart block

PRKAG2 mutations cause a glycogen storage cardiomyopathy that phenotypically mimics HCM but has distinct features: (1) LVH (from glycogen accumulation, not sarcomeric disarray); (2) pre-excitation (WPW pattern — from glycogen-filled bypass tracts); (3) progressive conduction disease (may require pacing); (4) short PR interval. It is a distinct entity from sarcomeric HCM with different management: mavacamten is not appropriate (not sarcomeric), the natural history includes risk of complete heart block and HF, and ICD considerations follow different criteria. The 2023 ESC Cardiomyopathy Guidelines classify it among metabolic/storage causes of hypertrophic phenotype (phenocopy). Genetic testing is essential for accurate diagnosis and management.

Reference: ESC (2023): Guidelines on Cardiomyopathies