microcephaly 9—primary—autosomal recessive
Definition A rare autosomal recessive disorder (OMIM:614852), defined as a head circumference > 3 standard deviations below the age-related mean, with a markedly reduced brain weight and disproportionately small cerebral cortex. Despite this marked reduction in size, the gyral pattern is relatively well preserved, with no major defects in cortical architecture. Affected individuals are mentally retarded. Primary microcephaly is unaccompanied by syndromic features or significant neurologic deficits due to degenerative brain disorder.
Molecular pathology Defects of CEP152, which encodes a protein involved in centrosome function, cause microcephaly 9—primary—autosomal recessive.