A congenital muscular dystrophy characterized by autosomal recessive inheritance of muscular dystrophy with mental retardation and structural brain abnormalities that has material basis in homozygous or compound heterozygous mutation in the LARGE gene on chromosome 22q12. The disease is MONDO_0012138 (muscular dystrophy-dystroglycanopathy type B6). Also known as: MDC1D, MDDGB6, congenital muscular dystrophy large-related, congenital muscular dystrophy type 1D, muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B, 6, muscular dystrophy-dystroglycanopathy (congenital with mental retardation), type B, 6.