ASPM and microcephaly: ,45 Moreover, mutations in several established microcephaly genes, such as ASPM (MIM: 605481),46CDK5RAP2 (MIM: 608201),47 and CENPJ (MIM: 609279),48 are known to likely disrupt such control, disturb the balance between proliferation and differentiation of the NPCs, and subsequently decrease the neural progenitor pool size.