Like other dystroglycanopathies, GMPPB mutations manifest with a spectrum of clinical features of variable severity, spanning from congenital muscular dystrophies (CMD) with brain and eye abnormalities to limb-girdle muscular dystrophies (LGMD) to exercise intolerance and rhabdomyolysis [6,7]. Here, GMPPB is linked to neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan.