The challenging diagnosis of dysferlinopathy – a case report

Abstract

Objectives. Dysferlinopathies are a group of rare genetic myopathies characterized by muscle weakness and atrophy with four distinct clinical phenotypes: Miyoshi myopathy, limb girdle muscular dystrophy type 2B, distal myopathy with anterior tibial onset and an intermediate proximo-distal phenotype. We report a case of dysferlinopathy and discuss relevant clinical, pathological and genetic data. Material and methods. We present the case of a 36 years old man with more than ten years history of progressive muscle weakness and atrophies in the distal lower limbs. He had a first clinical evaluation at the age of 24 years and a muscle biopsy was performed but it was inconclusive. On current admission, he presented with clinical suspicion of Charcot-Marie-Tooth disease, but because of increased serum creatine kinase levels and EMG (electromyography) findings of myopathy, another muscle biopsy was recommended. The muscle tissue obtained was analyzed by histopathology, immunohistochemistry, and Western blot techniques, and also a genetic confirmation was recommended. Results. Based on morphological findings, electrodiagnostic study results and clinical context, the diagnosis of primary dysferlinopathy was established, supported by genetic data. Conclusions. The diagnosis may be challenging in these rare genetic myopathies, due to the high variability of phenotypes, ranging from asymptomatic hyperCKemia (high serum creatine kinase level) to a severe clinical picture with loss of ambulation. Repeated evaluation, increasing access to genetic testing and a multidisciplinary approach made an accurate diagnosis possible in our case.

Keywords

• dysferlinopathies
• miyoshi myopathy
• distal myopathy
• limb girdle muscular dystrophy