FKRP and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan: Here we show that ribitol, a natural pentose alcohol present in some plants and animals and considered as a metabolic intermediate or end product, can effectively restore therapeutic levels of F-α-DG and, more importantly, ameliorate dystroglycanopathy caused by the FKRP P448L mutation, which is associated with severe CMD phenotype in clinic38,39.