Mental retardation and microcephaly with pontine and cerebellar hypoplasia – also known as mental retardation, X-linked, syndromic, Najm type ; X-linked intellectual deficit, Najm type; intellectual developmental disorder, X-linked, syndromic, Najm type; X-linked intellectual disability–microcephaly–pontocerebellar hypoplasia syndrome; and by variations of these terms – is a rare X-linked dominant genetic disorder of infants characterised by intellectual disability and pontocerebellar hypoplasia. Wikipedia