Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1

Congenital muscular dystrophies resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239) are characterized by early onset of muscle weakness, usually before ambulation is achieved; mental retardation and mild brain anomalies are variable (Balci et al., 2005; Godfrey et al., 2007). Congenital muscular dystrophy-dystroglycanopathies with or without impaired intellectual development (type B) represent the intermediate range of the spectrum of dystroglycanopathies. They are less severe than muscular dystrophy-dystroglycanopathy with brain and eye anomalies (type A; see MDDGA1, 236670), previously designated Walker-Warburg syndrome (WWS) or muscle-eye-brain disease (MEB), and more severe than limb-girdle muscular dystrophy-dystroglycanopathy (type C; see MDDGC1, 609308). Genetic Heterogeneity of Congenital Muscular Dystrophy-Dystroglycanopathy with or without Impaired Intellectual Development (Type B) Congenital muscular dystrophy with impaired intellectual development due to defective glycosylation of DAG1 is genetically heterogeneous. See also MDDGB2 (613156), caused by mutation in the POMT2 gene (607439); MDDGB3 (613151), caused by mutation in the POMGNT1 gene (606822); MDDGB4 (613152), caused by mutation in the FKTN gene (607440); MDDGB5 (616612), caused by mutation in the FKRP gene (606596); MDDGB6 (608840), caused by mutation in the LARGE gene (603590); MDDGB14 (615351), caused by mutation in the GMPPB gene (615320); and MDDGB15 (618992), caused by mutation in the DPM3 gene (605951).

OMIM