Muscular dystrophy includes many genetically distinct disorders. The list of causative genes for muscular dystrophy has been expanding rapidly, including those for congenital muscular dystrophies.We review the newly identified causative genes and suggested molecular mechanisms, focusing on glycosylation abnormality of alpha-dystroglycan, collagen VI deficiency, four allelic diseases of caveolin-3 gene, and titin gene mutations.Several possible mechanisms causing muscular dystrophy were discussed. Defects in extracellular molecules have more significant effects resulting mainly in congenital muscular dystrophy, while intracellular molecular defects show milder effect on the phenotype. These hypotheses may provide a new paradigm in understanding the pathomechanism of muscular dystrophies.