Congenital muscular dystrophy is a heterogeneous group of inherited autosomal recessive disorders with onset at birth or in early infancy, characterized by severe hypotonia, markedly delayed motor development, generalized muscle atrophy with weakness of limb and trunk muscles leading to contractures and joint deformities. Congenital muscular dystrophy 1B represents a heterogeneous group of conditions characterized by proximal girdle weakness, generalized muscle hypertrophy, and rigidity of the spine and contractures of the tendo Achilles.