Introduction Fetal or neonatal hypoxia (FoNH) is a known risk factor for schizophrenia. It has been hypothesized that FoNH induced expression of schizophrenia susceptibility genes (Schmidt-Kastner et al. 2012, Giannopoulou et al. 2018). Objectives To test this hypothesis, we explore the effects of FoNH and some genetic variants on age at onset (AAO) of schizophrenia. Methods The study included 1670 patients (women 1021 (61.1%), mean age 34.6 (SD 13.6), mean age at disease onset 25.4 (10.5) years) with ICD-10 diagnosis of schizophrenia or schizoaffective psychosis. The effects of FoNH in interaction with sex, family history (FH) and genetic variants on AAO of schizophrenia were evaluated. Polymorphisms rs2514218 DRD2 (n=943), Val66Met BDNF (n=820) and VNTR AS3MT (n=804) were genotyped. Results Among all patients studied 179 (10.8%) had experienced FoNH. Regression model showed that FoNH, sex and FH of schizophrenia contribute significantly (p=0.000) to AAO. In the FoNH group, AAO was lower compared to the group without FoNH (20.7 (6.2) vs 25.5 (10.) years). When comparing men and women, there was a difference between FoNH and non- FoNH subgroups only in women (p=0.000). No interaction between FH and FoNH was observed though positive FH had an effect on AAO. There was the interaction effect of VNTR AS3MT and FoNH on AAO. In the FoNH group, carriers of 2 repeats had younger AAO compared to the carriers homozygous for 3 repeat variant (19.6 (4.9) vs 22. (7.6) years). Conclusions We demonstrate the interaction effects of FoNH and VNTR AS3MT polymorphism on AAO of schizophrenia. Disclosure No significant relationships.

Introduction Oxytocin is considered as potential treatment targeting social dysfunctions in psychoses. However, results of clinical trials are inconsistent which may be due to genetic variation in the oxytocin system involved in social information processing. Objectives To examine the effect of the OXTR polymorphism and its interaction with childhood adversity (CA) on facial affect recognition (FAR) in psychotic patients. Methods Patients with schizophrenic and affective psychotic disorders (n=934) completed a task that required labeling six basic and three social emotions. The polymorphisms rs53576 and rs7632287 within the OXTR locus were genotyped and dichotomized based on prior research. For 65% of the sample, information on CA defined as parental alcoholism or psychiatric illness was collected. The polymorphisms’ role in FAR was assessed using ANCOVAs adjusted for sex, age, and diagnosis. Results After Bonferroni correction, there was a significant effect of rs53576, mainly driven by the difference between genotypes in the affective patients. GG-homozygotes recognized emotions better than A-allele carriers. A nominally significant effect in the expected direction was also found for rs7632287. CA influenced FAR but did not interact with any genotype. Conclusions The results provide further evidence that OXTR impacts social cognition and behavior in diverse cohorts, including psychotic patients, with rs53576 GG-homozygotes having enhanced social competencies. However, we have failed to confirm that OXTR modulates the relations between CA and FAR in psychosis. The difference in FAR between genotypes was more pronounced in affective patients, which might be due to more severe FAR deficits in schizophrenia. Disclosure No significant relationships.