Moreover, descriptions of cognitive impairment in patients with pathogenic variations in PRKDC [4] and in the three genes of the NHEJ ligation complex, NHEJ1/XLF [5], LIG4 [6] and XRCC4 [7] also revealed an essential role for the NHEJ complex in neurodevelopment [8]. The gene discussed is NHEJ1; the disease is Cognitive impairment.