| X-linked intellectual disability, Siderius type is characterized by mild to borderline intellectual deficit associated with cleft lip/palate. Preaxial polydactyly, large hands and cryptorchidism are sometimes present. The syndrome has been described in seven boys from two families. Transmission is X-linked and the syndrome is caused by mutations in the PHF8 gene, localized to the p11.21 region of the X chromosome. |
