Mondo Description Christianson syndrome is a very rare form of syndromic intellectual deficit characterized by microcephaly, severe developmental delay or regression, hypotonia, abnormal movements, and early-onset seizures.

Uniprot Description A syndrome characterized by profound mental retardation, epilepsy, ataxia, and microcephaly. It shows phenotypic overlap with Angelman syndrome.

Disease Ontology Description A syndromic X-linked intellectual disability characterized by severe developmental delay, intellectual disability, microcephaly, impaired speech, ataxia, hypotonia and early-onset seizures that has_material_basis_in mutation in the SLC9A6 gene on chromosome Xq26.