Next-generation sequencing to diagnose muscle disorders

Late-onset Pompe disease (LOPD) is a rare treatable lysosomal storage disorder characterized by progressive lysosomal glycogen accumulation and muscle weakness, with often a limb-girdle pattern. Despite published guidelines, testing for LOPD is often overlooked or delayed in adults, owing to its low frequency compared to other muscle disorders with similar muscle patterns. Next-generation sequencing (NGS) has the capability to test concurrently for several muscle disorders. This could potentially lead to increased diagnosis of LOPD, disorders with non-specific muscle weakness or atypical patients. The authors have developed a gene panel to simultaneously analyze genes associated with several muscle disorders with overlapping phenotypes in order to increase the diagnosis of LOPD in children and adults, of other disorders with non-specific muscle patterns and of patients with atypical presentations. In another study, Angelini and colleagues report on the use of NGS to reconsider the diagnosis of LGMD of unknown aetiology in a patient in whom the diagnosis was delayed for 30 years. These studies highlight the high clinical utility of gene panels in patients with suspected muscle disorders and its potential to facilitate the diagnosis of patients showing non-specific muscle weakness or atypical phenotypes. They propose that gene panels should be used as a first-tier test in patients with suspected muscle disorders of undetermined etiology, which could further increase overall diagnosis of muscle conditions, and potentially reduce diagnostic delay.

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Lévesque S, Auray-Blais C, Gravel E, et al. Diagnosis of late-onset Pompe disease and other muscle disorders by next-generation sequencing. Orphanet  J Rare Dis. 2016 Jan 25;11(1):8.

Angelini C, Savarese M, Fanin M, Nigro V. Next generation sequencing detection of late onset Pompe disease. Muscle Nerve. 2016 Jan 21. doi: 10.1002/mus.25042. [Epub ahead of print]