XRCC1 and schizophrenia: Indeed, several studies have shown that genetic polymorphisms in the core BER-protein XRCC1 or in XRCC1 interacting proteins such as 8-oxoguanine glycosylase (Ogg1) are implicated in patients with schizophrenia [24–27], ASD [28, 29] and bipolar disorder [30].