Background: ASPM (abnormal spindle-like microcephaly associated) is also known as MCPH5 (autosomal recessive primary microcephaly 5). Defects in ASPM are the cause of microcephaly primary type 5 or microcephaly vera, an autosomal recessive disease characterized by reduced head circumference, small cerebral cortex, and reduced brain weight. At the cellular level, MCPH5 is important to mitotic spindle function and may play a preferential role in prenatal neurogenesis.