A rare cerebellar dysgenesis syndrome characterized by variable clinical manifestations ranging from mild intellectual deficit with or without congenital nystagmus, to severe cognitive impairment associated with cerebellar and pontine hypoplasia/atrophy and abnormalities of cortical development. The disease is syndromic X-linked intellectual disability Najm type (MONDO_0010417, a Monarch Disease Ontology id). Also known as: MICPCH, MICPCH syndrome, X-linked intellectual disability-microcephaly-pontocerebellar hypoplasia syndrome, intellectual disability and microcephaly with pontine and cerebellar hypoplasia, mental retardation and microcephaly with PONTINE and cerebellar hypoplasia, mental retardation and microcephaly with pontine and cerebellar hypoplasia, mental retardation, X-linked, syndromic, Najm type.