Very late-onset limb-girdle muscular dystrophy type 2D: A milder form with a normal muscle biopsy

Sarcoglycanopathies are a genetically heterogeneous group of autosomal recessive limb-girdle muscular dystrophies (LGMD) caused by mutations in sarcoglycan genes. We report a Portuguese patient with a very late-onset LGMD phenotype, whose muscle biopsy and immunostaining, in particular for α-sarcoglycan, were unrevealing. Muscle MRI showed a predominant, bilateral and symmetric involvement of the tight muscles and also, to a lesser extent, of the posterior compartment of lower legs muscles. Next generation sequencing (NGS) revealed a known homozygous c.850C > T (p.Arg284Cys) mutation in SGCA gene. Milder forms of α-sarcoglycanopathies could be a challenging diagnosis; particularly if muscle histopathology and α-sarcoglycan immunohistochemistry are unhelpful. NGS plays a crucial role not only for aiding in the establishment of a definite diagnosis, but also for expanding clinical presentations.