Common variants in FAN1, located in 15q13.3, confer risk for schizophrenia and bipolar disorder in Han Chinese.

Multiple genetic risk factors have been associated with psychiatric disorders which provides the genetic insight to these disorders; however, the etiology of these disorders is still elusive. 15q13.3 was previously associated with schizophrenia, bipolar and other neurodevelopmental disorders. Whereas, the FAN1 which encodes the Fanconi anemia associated nuclease 1 was suggested to be causal gene for 15q13.3 related psychiatric disorders. This study aimed to investigate the association of FAN1 with three major psychiatric disorders. Herein, we conducted a case-control study with the Chinese Han population. Three single nucleotide polymorphisms (SNPs) of FAN1 were genotyped in 1248 schizophrenia cases, 1344 bipolar disorder cases, 1056 major depressive disorder cases and 1248 normal controls. We found that SNPs rs7171212 was associated with bipolar (p = 0.023, p = 0.022, OR = 0.658) and schizophrenia (p = 0.021, p = 0.019, OR = 0.645). Whereas, rs4779796 was associated with schizophrenia (p = 0.001, adjusted p = 0.003, OR = 1.089). In addition, rs7171212 (adjusted p = 0.018, adjusted p = 0.018, OR = 0.652) and rs4779796 (adjusted p = 0.024, OR = 1.12) showed significantly associated with combined cases of schizophrenia and bipolar disorder. Further, meta-analysis was performed with the case-control data and dataset extracted from previously reported genome-wide association study to validate the promising SNPs. Our results provide the new evidence that FAN1 may be a common susceptibility gene for schizophrenia and bipolar disorder in Han Chinese. These novel findings need further validation with larger sample size and functional characterization to understand the underlying pathogenic mechanism behind FAN1 in the prevalence of schizophrenia and bipolar disorders.