Our patient had a deletion of chromosome 3q22.2q23, which does not include the ATR gene but does include the PIK3CB gene as a candidate gene for microcephaly.
Seckel syndrome, a rare genetic disorder characterized by a microcephaly and a markedly reduced body size, has been associated with defective ATR-dependent DNA damage signaling.
ATR-ATRIP patients are characterised by extremely severe microcephaly and growth delay, microtia (small ears), micrognathia (small and receding chin), and dental crowding.
Important insights into human neurogenesis are being revealed by the study of rare genetic diseases that involve primary microcephaly, illustrated by the identification of the Microcephalin, abnormal spindle in microcephaly and ataxia-telangiectasia and Rad3-related genes.