The role of PNKP in DNA repair, especially of SSBs, and its implication in the pathology of several autosomal recessive neurodegenerative diseases, including AOA4 (Ataxia-ocular motor apraxia 4), CMT2B2 (Charcot–Marie–Tooth disease) and MCSZ (Microcephaly, seizures, and developmental delay) have been described in various studies [65]. The gene discussed is PNKP; the disease is microcephaly.