This case report presents a 27-year-old male born to consanguineous Burmese parents, who was admitted to hospital due to per-rectal bleeding. He was incidentally found to have hypocalcaemia, vitamin D deficiency, and elevated parathyroid hormone. An electrocardiogram displayed a Wolff-Parkinson-White (WPW) pattern, despite the patient's lack of cardiac symptoms or awareness of this condition. Further questioning revealed a family history of sudden cardiac death and mobility impairments among male relatives on the paternal side. He did not show any phenotypic characteristics of muscular dystrophy.
Chromosome microarray analysis showed an exon deletion within the Duchenne Muscular Dystrophy (DMD) gene on the X-chromosome. Becker muscular dystrophy arises from mutations in the DMD gene, leading to the absence of dystrophin in muscle tissue. (1) This deficiency disrupts calcium homeostasis, causing dysregulated calcium influx and impaired clearance within muscle cells. Consequently, intracellular calcium accumulates, affecting both skeletal and cardiac muscles, resulting in cardiomyopathy and potential damage to the cardiac conduction system. (2,3,4,5,6).
Notably, this case report highlights the infrequent presentation of isolated biochemical disturbance and ECG changes within the context of muscular dystrophy. Recognizing the atypical yet meaningful presentations of muscular dystrophy, such as hypocalcaemia and WPW syndrome, underscores the necessity of an interdisciplinary approach. This approach involves genetic testing, clinical assessment, and cardiovascular evaluation to comprehensively grasp the diverse clinical manifestations associated with muscular dystrophy.
Keywords: muscular dystrophy, hypocalcaemia, vitamin D deficiency, Wolff-Parkinson-White syndrome, Duchenne Muscular Dystrophy, calcium homeostasis, cardiomyopathy.