Myoadenylate-deaminase gene mutation associated with left ventricular hypertrabeculation/non-compaction

Abstract

Background — Left ventricular hypertrabeculation (LVHT)/non-compaction, a rare myocardial abnormality and frequently associated with neuromuscular disorders, has not been reported in primary myoadenylate-deaminase (MAD) deficiency (MADD).

Case report — In a 53-year-old man with easy fatigability and myalgia since boyhood, primary MADD was diagnosed based upon slightly, but recurrently elevated creatine-kinase, absent staining for MAD on muscle biopsy, markedly reduced MAD activity in the muscle homogenate, and the C34T mutation within exon 2 of the AMPD1 gene. An ambulatory ECG showed nocturnal sinus bradycardia and echocardiography thickening of the interventricular septum (20 mm) and the posterior wall (16 mm) and additionally LVHT. Cardiac MRI confirmed myocardial thickening and LVHT. Myocardial thickening and LVHT were regarded as causally related to the C34T mutation.

Conclusion — Cardiac involvement in MADD may manifest as left ventricular myocardial thickening and LVHT. MADD should be included in the list of neuromuscular disorders which are associated with LVHT.

Key Words:

• metabolic myopathy
• muscle cramps
• myalgia
• non-compaction
• cardiac involvement
• cardiomyopathy