MCPH1 and autosomal recessive primary microcephaly: ASPM (MCPH5) is reported as being the most common locus for MCPH, with WDR62 (MCPH2) being the second, followed by MCPH1 and the other loci being rarer causes of MCPH (Roberts et al., 2002; Darvish et al., 2010; Nicholas et al., 2010; Sajid Hussain et al., 2013).