The interaction between estradiol change and the serotonin transporter gene (5-HTTLPR) polymorphism is associated with postpartum depressive symptoms Although estrogenic fluctuation is considered a major risk factor for postpartum depression (PPD), the effects of the interactions between the genetic background and estradiol (E2) change on PPD are not well understood. Here, a cohort study with 437 postpartum women was carried out to evaluate the role of a serotonin transporter gene polymorphism (5-HTTLPR) and E2 change on the risk of PPD symptoms. The participants were assessed using the Edinburgh Postnatal Depression Scale and the Self-Rating Depression Scale at 1 and 6 weeks after delivery. The PCR-based restriction fragment length polymorphism method was utilized to examine the genotype distribution of the 5-HTTLPR polymorphism, and the serum levels of E2 were determined in individuals in the third trimester of pregnancy and at 1 week postpartum. A significant association was observed between E2 change and PPD susceptibility in the late postpartum period (6 weeks) [P = 0.002, odds ratio (OR) = 2.341, 95% confidence interval (CI) = 1.361–4.027], but it was not observed in the early postpartum period (1 week). There was no significant association between the 5-HTTLPR genotype and PPD risk at both the early and late postpartum periods (P > 0.05). However, the interaction between E2 change and the 5-HTTLPR polymorphism could reasonably influence PPD risk. The women who carried the SS genotype with large decreases in E2 showed a significantly higher risk for PPD at both the early (P = 0.002, OR = 2.525, 95% CI = 1.384–4.059) and late postpartum periods (P < 0.001, OR = 3.108, 95% CI = 1.562–4.436) compared with those who carried the SL/LL genotype. This study suggests that there is an association between E2 change in the perinatal period with the 5-HTTLPR genotype and the occurrence of PPD.

Anorexia nervosa is associated with Neuronatin variants Background Anorexia nervosa is a complex neuropsychiatric disorder presenting with life-threatening low body weight, and a persistent fear of gaining weight. To date, no whole exome sequencing was performed in male individuals with anorexia nervosa. Aim and Methods Here, we performed an exome analysis in two independent families with male individuals with anorexia nervosa and found variants in the Neuronatin (NNAT) gene in both probands. To confirm our data, we carried out the screening of the NNAT gene in a cohort of 8 male and 144 female individuals with anorexia nervosa. Results Exome sequencing revealed a nonsense variant p.Trp33* in NNAT in one patient and a rare variant in the 5′UTR region of NNAT in the other patient. Screening of the NNAT gene in a cohort of 8 male and 144 female individuals with anorexia nervosa allowed to identify 11 other NNAT variants showing that 40.00% and 6.25% of male and female anorexia nervosa individuals carried a NNAT variant, respectively. Moreover, two novel missense variants were identified in female anorexia nervosa patients. Conclusion Our data suggest that NNAT variants and NNAT expression changes may be associated with susceptibility to eating disorders such as anorexia nervosa.

Determining population stratification and subgroup effects in association studies of rare genetic variants for nicotine dependence Background Rare variants (minor allele frequency < 1% or 5 %) can help researchers to deal with the confounding issue of ‘missing heritability’ and have a proven role in dissecting the etiology for human diseases and complex traits. Methods We extended the combined multivariate and collapsing (CMC) and weighted sum statistic (WSS) methods and accounted for the effects of population stratification and subgroup effects using stratified analyses by the principal component analysis, named here as ‘str-CMC’ and ‘str-WSS’. To evaluate the validity of the extended methods, we analyzed the Genetic Architecture of Smoking and Smoking Cessation database, which includes African Americans and European Americans genotyped on Illumina Human Omni2.5, and we compared the results with those obtained with the sequence kernel association test (SKAT) and its modification, SKAT-O that included population stratification and subgroup effect as covariates. We utilized the Cochran–Mantel–Haenszel test to check for possible differences in single nucleotide polymorphism allele frequency between subgroups within a gene. We aimed to detect rare variants and considered population stratification and subgroup effects in the genomic region containing 39 acetylcholine receptor-related genes. Results The Cochran–Mantel–Haenszel test as applied to GABRG2 (P = 0.001) was significant. However, GABRG2 was detected both by str-CMC (P= 8.04E-06) and str-WSS (P= 0.046) in African Americans but not by SKAT or SKAT-O. Conclusions Our results imply that if associated rare variants are only specific to a subgroup, a stratified analysis might be a better approach than a combined analysis.

Common variants in SATB2 are associated with schizophrenia in Uygur Chinese population Objective Schizophrenia is one of the most severe mental disorders and its etiology is supposed to be an interaction between genes and environmental factors. Previous genome-wide association studies of schizophrenia have reported multiple susceptibility loci including rs6704641 in the SATB2 gene. Recently, this locus was further confirmed as a genome-wide significant locus for association with schizophrenia by trans-ancestry meta-analysis of Han Chinese and Caucasian samples. However, there is no report of genetic analysis in Uygur Chinese population, which is considered to have a combined genetic background between eastern Asia and Caucasian. This study is aimed to explore whether SATB2 gene is significantly associated with schizophrenia in Uygur Chinese population, thus providing additional evidence for elucidating the role of SATB2 gene in schizophrenia. Participants and methods In this study, we performed a case–control analysis focusing on seven tag single nucleotide polymorphisms located in SATB2 gene among 985 patients with schizophrenia and 1218 healthy controls recruited from the Xinjiang Province of China. Results We found that rs6704641 was significantly associated with schizophrenia in both allelic and genotypic distributions (Pallele = 0.008, Pgenotype = 0.028 after correction). In addition, rs16831466 is significantly associated with schizophrenia in allelic distributions (corrected Pallele = 0.041). Besides, several haplotypes of single nucleotide polymorphism are significantly associated with schizophrenia too. Conclusion Our results suggest that SATB2 is also a susceptibility gene for schizophrenia in Uygur Chinese population, and subsequent functional experiments are necessary to reveal its role in the pathogenesis.

Decreased serum complement component 4 levels in patients with schizophrenia Dysregulation of the immune system in mental disease, particularly complement component 4 (C4), which may be associated with schizophrenia, has been repeatedly observed. This study investigated the association between the level of serum component 4 and schizophrenia. Data were derived from a case-control association study of 40 unrelated adult patients with schizophrenia and 40 matched healthy controls. The component 4 level in serum was measured for comparative analysis by a component 4 enzyme-linked immunosorbent assay kit. Our findings suggest that the serum component 4 level is lower in patients with schizophrenia than in the controls, and the results apply to both males and females. Our results will lay an important foundation for establishing diagnostic methods and provide feasible and reliable evidence for the clinical treatment of schizophrenia.