Microcephalin 1 (MCPH1)

Microcephalin is one of six genes causing primary microcephaly when non-functional mutations exist in the homozygous state. Derived from the Greek words for "small" and "head", this condition is characterised by a severely diminished brain. Hence it has been assumed that variants have a role in brain development, but in normal individuals no effect on mental ability, brain size or behavior has been attributed to either this or another similarly studied microcephaly gene, ASPM.

MCPH1 is expressed in the fetal brain, in the developing forebrain, and on the walls of the lateral ventricles. Cells of this area divide, producing neurons that migrate to eventually form the cerebral cortex.