VMA21-X-linked myopathy in Peru: characterization of three families

VMA21-X-Linked related myopathy is a rare neuromuscular disease characterized by a wide phenotypic spectrum ranging from neonatal forms with severe muscular weakness and respiratory failure, to mild childhood or adult-onset forms with slowly progressive muscular weakness and variably elevated serum creatine kinases. This condition is also called X-linked myopathy with excessive autophagy (XMEA) due to the presence of autophagic vacuoles with sarcolemmal proteins. Here we describe the clinical, muscle imaging, and genetic findings of six VMA21-X-Linked related myopathy patients belonging to three unrelated Peruvian families. Lower limb proximal muscle weakness and extraocular muscles involvement leading to upward ophtalmoparesis are the main clinical features in our cohort. Lower limb muscle MRI showed a typical pattern with major involvement of antero-medial compartment of thigh, and relative sparing of rectus femoris, gracilis, adductor longus. This is the first report of the VMA21-X-Linked related myopathy in Peru.