Novel ANO5 homozygous microdeletion causing myalgia and unprovoked rhabdomyolysis in an Arabic man

• Published in: Muscle & nerve Vol. 50; no. 4; pp. 610 - 613
• Main Authors: Lahoria, Rajat, Winder, Thomas L., Lui, Jie, Al‐Owain, Mohammed A., Milone, Margherita
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.10.2014
• Subjects: amyloidosis; ANO5; ANO5 deletion; anoctaminopathy; Anoctamins; Biopsy; Chloride Channels - genetics; Homozygote; Humans; hyper‐CK‐emia; Magnetic Resonance Imaging; Male; Middle Aged; Muscle, Skeletal - pathology; Muscular dystrophy; Mutation; Mutation - genetics; Myalgia - complications; Myalgia - genetics; Myalgia - pathology; pseudometabolic myopathy; rhabdomyolysis; Rhabdomyolysis - complications; Rhabdomyolysis - genetics; Rhabdomyolysis - pathology; muscular dystrophy; rhabdomyolysis; amyloidosis; hyper-CK-emia; anoctaminopathy; ANO5; ANO5 deletion; pseudometabolic myopathy
• ISSN: 0148-639X; 1097-4598; 1097-4598
• DOI: 10.1002/mus.24302

ABSTRACT Introduction: Recessive mutations in the anoctamin‐5 gene (ANO5) cause a spectrum of clinical phenotypes, including limb‐girdle muscular dystrophy (LGMD 2L), distal myopathy, and asymptomatic hyperCKemia. Methods: In this report we describe our clinical, electrophysiological, pathological, and molecular findings in a subject with anoctaminopathy‐5. Results: A 49‐year‐old Arabic man from a consanguineous family presented with a 5‐year history of myalgias, hyperCKemia and an episode of unprovoked rhabdomyolysis. Muscle biopsy showed mild myopathic changes and interstitial amyloid deposition. ANO5 analysis detected a novel homozygous deletion of approximately 11.9 kb encompassing exons 13–17, predicted to be pathogenic. Conclusions: Anoctaminopathy‐5 can manifest with a phenotype reminiscent of metabolic myopathy and should be considered as a potential cause of myalgia and myoglobinuria. Amyloid deposition in the muscle biopsy is helpful for the diagnosis. A novel homozygous ANO5 deletion was identified, suggesting that screening for common mutations may have low yield in non‐European subjects. Muscle Nerve 50: 610–613, 2014