Alpha-sarcoglycanopathy presenting as myalgia and hyperCKemia in two adults with a long-term follow-up. Case reports.

Two patients with a paucisymptomatic hyperckemia underwent a skeletal muscle biopsy and massive gene panel to investigate mutations associated with inherited muscle disorders. In the SGCA gene, sequence analyses revealed a homozygous c.850C > T/p.Arg284Cys in patient 1 and two heterozygous variants (c.739G > A/p.Val247Met and c.850C > T/p.Arg284Cys) in patient 2. Combination of histology and immunofluorence studies showed minimal changes for muscular proteins including the α-sarcoglycan. These two cases highlight the advantages of next-generation sequencing in the differential diagnosis of mild myopathic conditions before considering the more invasive muscle biopsy in sarcoglycanopathies.

Milder forms of α-sarcoglicanopathies diagnosed in adulthood by NGS analysis.

INTRODUCTION: Sarcoglycanopathies (LGMD 2C2F) are a subgroup of limb-girdle muscular dystrophies (LGMD), caused by mutations in sarcoglycan genes. They usually have a childhood onset and rapidly progressive course with loss of ability to walk over 12-16 years. METHODS: Next generation sequencing (NGS) targeted gene panel was performed in three adult patients with progressive muscle weakness in which routine muscle histology and immunohistochemistry were not diagnostic. RESULTS: Genetic analysis revealed homozygous or compound heterozygous mutations in SGCA gene and Western Blot demonstrated protein reduction confirming the diagnosis of α-sarcoglicanopathy. DISCUSSION: Our cases evidence that the diagnosis of mild forms of alfa sarcoglicanopathy could be a challenge and suggest the possibility that they could be underdiagnosed. The use of Next generation Sequencing targeted gene panels is very helpful in the diagnosis of these patients.