A, Pedigree of the consanguineous family A of Pakistani descent with two patients affected by microcephaly (□, male; ○, female; ═, consanguineous marriage); B, Sanger sequencing results of patient IV.2 from family A showing a homozygous mutation c.4802C>G in the ASPM gene that leads to a nonsense mutation p.S1601* (red arrow). The parental control III.2 is heterozygous for the ASPM mutation.