Congenital muscular dystrophy due to fukutin mutations without ocular symptoms and central nervous system disorders: A case report

We report a 22-year-old Japanese man with severe congenital muscular dystrophy without intellectual disability due to a 3-kb retrotransposal insertion and point mutation in the fukutin gene ( FKTN ), classified as congenital muscular dystrophy-dystroglycanopathy without mental retardation (type B4; MDDGB4; OMIM 613152 ). The onset was in infancy, and while he eventually lost his ambulation, he had no intellectual disability. We believe that this patient had the most severe MDDGB4 phenotype not only among surviving patients with FKTN mutations but also among surviving patients with mutations in other α-dystroglycanopathy-related genes. The phenotypes associated with FKTN mutations are not limited to FCMD, ranging from severe to mild in manifestation.