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Background: Leprosy is a chronic infectious skin and neurological disease, and genetic background is considered to be one of the major factors of risk. The major histocompatibility complex (MHC) region not only affects susceptibility to leprosy but also its development and outcome. Given the complex traits of the MHC region, variants and the potential mechanism by which HLA influences leprosy development need to be further explored. Methods: We extracted previous genome-wide association study data from the Northern Han Chinese population to perform HLA fine-mapping. Using the 1,000 Genome Project Phase 3 dataset as the reference panel, single-nucleotide polymorphisms (SNP), insertion and deletion (INDEL) and copy number variant (CNV) imputation were carried out. HLA classical alleles and amino acids in the MHC region were imputed using the HAN-MHC database. Further stepwise regression analysis was conducted to analyze independent signals of variants related to leprosy. Results: We identified four independent variants: esv3608598, rs7754498, rs3130781 and rs144388449. Among them, esv3608598 is a CNV and the first HLA CNV associated with leprosy risk. SNP annotation using RegulomeDB, HaploReg, and rVarBase showed that three SNPs are likely to affect the pathogenesis of leprosy. Conclusion: In summary, this is the first study to assess the association between HLA CNV and leprosy susceptibility in a Northern Han Chinese population. By fine mapping of the MHC region in this population, our findings provide evidence for the contribution of HLA to leprosy susceptibility. [ABSTRACT FROM AUTHOR]

Objective: Genome‐wide association studies have identified many susceptibility loci for systemic lupus erythematosus (SLE). However, most of these loci are located in noncoding regions of the genome. Long noncoding RNAs (lncRNAs) are pervasively expressed and have been reported to be involved in various diseases. This study aimed to explore the genetic significance of lncRNAs in SLE. Methods: A genome‐wide survey of SLE risk variants in lncRNA gene loci was performed in Han Chinese subjects (4,556 with SLE and 9,451 healthy controls). The functional relevance of an SLE risk variant in one of the lncRNA genes was explored using biochemical and molecular cell biology analyses. In vitro loss‐of‐function and gain‐of‐function strategies were used to clarify the functional and phenotypic relevance of this SLE susceptibility lncRNA. Moreover, correlation of this lncRNA with the degree of apoptosis in the peripheral blood of SLE patients was evaluated. Results: A novel SLE susceptibility locus in a lncRNA gene, designated SLEAR (for SLE‐associated RNA), was identified at the single‐nucleotide polymorphism rs13259960 (odds ratio 1.35, Pcombined = 1.03 × 10−11). The A>G variation at rs13259960, located in an intronic enhancer, was found to impair STAT1 recruitment to the enhancer that loops to the SLEAR promoter, resulting in decreased SLEAR production in peripheral blood mononuclear cells from patients with SLE (3 with the G/G genotype, 22 with A/G, and 103 with A/A at rs13259960; P = 0.0241). Moreover, SLEAR interacted with the RNA binding proteins interleukin enhancer binding factor 2, heterogeneous nuclear RNP F, and TATA‐binding protein–associated factor 15, to form a complex for transcriptional activation of the downstream antiapoptotic genes. In addition, SLEAR regulated apoptosis of Jurkat cells in vitro, and its expression level was correlated with the degree of cell death in the peripheral blood of patients with SLE (r = 0.824, P = 2.15 × 10−8; n = 30). Conclusion: These findings suggest a mechanism by which the risk variant at rs13259960 modulates SLEAR expression and confers a predisposition to SLE. Taken together, these results may give insights into the etiology of SLE. [ABSTRACT FROM AUTHOR]

Psoriasis vulgaris is a chronic inflammatory skin disease associated with complex genetic susceptibility. Recently, we identified a single-nucleotide variant rs1020760 at NFKB1 significantly associated with psoriasis in a Han Chinese population in deep analysis of exome and targeted sequencing ( P = 1.76 × 10−8). To investigate the potential association between rs1020760 and phenotypes of psoriasis vulgaris, we performed a genotype-phenotype analysis. A total of 9946 cases and 9906 controls with detailed clinical and demographic information were involved in this study, while the genotype data of rs1020760 was available in the previous targeted sequencing study of psoriasis. Genotype-based association testing revealed the additive model might provide the best fit for rs1020760 ( P = 5.44 × 10−8). Case-only analysis showed that the distribution of allele G was significantly different between the cases with and without family history ( Pallele = 4.07 × 10−3, Pgenotype = 5.75 × 10−3). The differences in allele and genotype frequencies were observed between all the subphenotypes and controls except for the genotype frequency of the late onset subgroup, while no difference was found in case-only analysis for the other two subphenotypes. Rs1020760 was preferentially associated with family history of psoriasis, implying that NFKB1 might not only play important roles in the development of psoriasis, but might also contribute to the special phenotypes of this disease. [ABSTRACT FROM AUTHOR]

Atopic dermatitis is a chronic inflammatory skin disease and is affected by environmental and genetic factors. Gene-gene/environment interactions are strongly believed to contribute to the genetic risk of common diseases. A number of gene-environment interactions of atopic dermatitis were performed. However, there are few comprehensive investigations on the gene-gene (or genetic variants) interactions for atopic dermatitis. We explored the association model of 6 single nucleotide polymorphisms (SNPs) which were most significant ( P < 10E-05) in our previous genome wide association study (GWAS) for atopic dermatitis, and search for the possible genetic variant interactions based on the previous GWAS data using Generalized Multifactor Dimensionality Reduction and Plink 1.07 in the combined sample of 4,636 cases and 13,559 controls. The most significant associated evidence was observed under dominant model for SNPs rs3126085, rs12085366, and rs7701890, recessive model for SNP rs17173197, and additive model for SNPs rs2393903 and rs6010620. Three significant pair-way interactions were observed, including PRKAG2 and FLG SNPs (rs17173197 × rs3126085, P = 1.11E-15), PRKAG2 and TMEM232- SLC25A46 SNPs (rs17173197 × rs7701890, P = 2.22E-15), PRKAG2 and TNFRSF6B- ZGPAT SNPs (rs17173197 × rs6010620, P = 6.66E-16). Besides, a three-way significant interaction among PRKAG2, TMEM232- SLC25A46 and TNFRSF6B- ZGPAT SNPs (rs17173197 × rs7701890 × rs6010620, P = 5.99E-15) was observed in this study. These four genetic variant interactions confer susceptibility to atopic dermatitis, and highlight the genetic variant interactions in the etiology of atopic dermatitis in Chinese Han population. [ABSTRACT FROM AUTHOR]

Generalized vitiligo is an autoimmune disease characterized by melanocyte loss, which results in patchy depigmentation of skin and hair, and is associated with an elevated risk of other immune-related diseases. However, there is no reported study on the associations between immune susceptibility polymorphisms and the risk of vitiligo with immune-related diseases. The aim of this study was to evaluate the potential influence of 10 single-nucleotide polymorphisms (SNPs) at 18q21.31 (rs10503019), 4p16.1 (rs11940117), 3q28 (rs1464510), 14q12 (rs2273844), 12q13.2 (rs2456973), 16q12.2 (rs3213758), 10q25.3 (rs4353229), 3q13.33 (rs59374417), and 10p15.1 (rs706779 and rs7090530) on vitiligo with immune-related diseases in the Chinese Han population. All SNPs were genotyped in 552 patients with vitiligo-associated immune-related diseases and 1656 controls using the Sequenom MassArray system. Data were analyzed with PLINK 1.07 software. The C allele of rs2456973 at 12q13.2 was observed to be significantly associated with vitiligo-associated immune-related diseases (autoimmune diseases and allergic diseases) ( P = 0.0028, odds ratio (OR) = 1.27). In subphenotype analysis, the rs2456973 C allele was also significantly associated with early-onset vitiligo by comparing with controls ( P = 0.0001) and in the case-only analysis (P = 0.0114). We confirmed that 12q13.2 was an important candidate locus for vitiligo with immune-related diseases (autoimmune diseases and allergic diseases) and affected disease phenotypes with early onset. [ABSTRACT FROM AUTHOR]

Background Vitiligo has been found to be associated with different HLA antigens in different ethnic groups. In our previous genome-wide association study (GWAS), we identified independent association signal of rs9468925 ( P = 2.21 × 10−33, OR = 0.74) within HLA-C-HLA-B region. Objectives To explore the association between rs9468925 polymorphism within MHC and the clinical features of generalized vitiligo. Methods The study, using 5566 cases and 6462 controls from previous GWA study investigated the single and combined (GA + GG) genotypic distribution of rs9468925 in subsets of vitiligo patients having different clinical features. We performed a QTL analysis (quantitative trait locus) for age of onset with genotype of rs9468925. Results The GA + GG genotypic distribution of SNP rs9468925 tested with an additive model was found to be significantly different in subgroups of patients of >20 vs. <20 years old (genotypic P = 2.57 × 10−4, combined P = 3.0 × 10−3, OR = 0.77, 95% CI: 0.64-0.92), and in patients with different clinical subtypes of vitiligo (genotypic P = 0.03, combined P = 5.0 × 10−3). However, there was no statistical significance for familial history, halo nevi involvement and autoimmune disease involvement. Conclusions Allele G of rs9468925 on HLA-C-HLA-B may be associated with a higher risk of vitiligo. Our study showed a significant genotypic variation between patients with age of onset ≤20 years and age of onset >20 years. Obvious clinical differences of generalized vitiligo related to genotypic variation found in the Chinese Han population were confirmed in this study. [ABSTRACT FROM AUTHOR]

Motivation: Despite the prevalence of copy number variation (CNV) in the human genome, only a handful of confirmed associations have been reported between common CNVs and complex disease. This may be partially attributed to the difficulty in accurately genotyping CNVs in large cohorts using array-based technologies. Exome sequencing is now widely being applied to case–control cohorts and presents an exciting opportunity to look for common CNVs associated with disease.Results: We developed ExoCNVTest: an exome sequencing analysis pipeline to identify disease-associated CNVs and to generate absolute copy number genotypes at putatively associated loci. Our method re-discovered the LCE3B_LCE3C CNV association with psoriasis (P-value = 5 × 10e−6) while controlling inflation of test statistics (λ < 1). ExoCNVTest-derived absolute CNV genotypes were 97.4% concordant with PCR-derived genotypes at this locus.Availability and implementation: ExoCNVTest has been implemented in Java and R and is freely available from www1.imperial.ac.uk/medicine/people/l.coin/.Contact: wangj@genomics.org.cn or Lachlan.J.M.Coin@genomics.org.cn [ABSTRACT FROM AUTHOR]

Vitiligo is an immune-related disease with patchy depigmentation of skin and hair caused by selective destruction of melanocytes. In recent decades, many studies have shown the association between vitiligo and HLA genes; however, the results of Han Chinese are scarce. In this study, we performed a fine-mapping analysis of the MHC region in 2818 Han Chinese subjects through a widely used HLA imputation method with a newly built large-scale Han-MHC reference panel. Three new four-digit HLA alleles ( HLA-DQB1  ∗  02:02 , HLA-DQA1  ∗  02:01 and HLA-DPB1  ∗  17:01 ) were identified to be associated with the risk of vitiligo, and four previously reported alleles were confirmed. Further conditional analysis revealed that two important variants, HLA-DQβ1 amino acid position 135 (OR = 1.79, P  = 1.87 × 10 −11 ) and HLA-B amino acid positions 45–46 (OR = 1.44, P  = 5.61 × 10 −11 ), conferred most of the MHC associations. Three-dimension ribbon models showed that the former is located within the β2 domain of the HLA-DQβ1 molecule, and the latter lies in the α1 domain of the HLA-B molecule, while both are involved in specific antigen presenting process. Finally, we summarized all significant signals in the MHC region to clarify their complex relationships, and 8.60% of phenotypic variance could be explained based on all reported variants in Han Chinese so far. Our findings highlight the complex genetic architecture of the MHC region for vitiligo in Han Chinese population and expand our understanding of the roles of HLA coding variants in the etiology of vitiligo. [ABSTRACT FROM AUTHOR]

Background Vitiligo is an autoimmune disease, characterized by progressive loss of skin pigmentation, which is caused by the interactions of multiple factors, such as heredity, immunity and environment. Recently, a single nucleotide polymorphism (SNP) rs638893 at 11q23.3 region was identified as a risk factor for vitiligo in genome-wide association studies and multiple SNPs in this region have been associated with other autoimmune diseases. Objective This study aims to identify additional susceptibility variants associated with vitiligo at 11q23.3 in the Chinese Han population. Methods We selected and genotyped 26 SNPs at 11q23.3 in an independent cohort including 2924 cases and 4048 controls using the Sequenom MassArray iPLEX ® system. Bonferroni adjustment was used for multiple comparisons and P value <1.92 × 10 −3 (0.05/26) was considered statistically significant. Results The A allele of rs613791 and G allele of rs523604 located in CXCR5 were observed to be significantly associated with vitiligo (OR = 1.21, 95% CI: 1.11–1.31, P = 1.20 × 10 −5 ; OR = 1.14, 95% CI: 1.07–1.23, P = 1.90 × 10 −4 , respectively). The C allele of rs638893 (a previously reported one) located upstream of DDX6 was also significantly associated with vitiligo (OR = 1.25, 95% CI: 1.12–1.38, P = 3.04 × 10 −5 ). The genotypes distribution of 3 SNPs also showed significant differences between case and control (rs613791: P = 7.00 × 10 −6 , rs523604: P = 4.00 × 10 −3 , rs638893: P = 1.20 × 10 −5 , respectively). The two newly identified SNPs (rs613791 and rs523604) showed independent associations with vitiligo by linkage disequilibrium analysis and conditional logistic regression. Conclusions The study identified two new independent signals in the associated locus 11q23.3 for vitiligo. The presence of multiple independent variants emphasizes an important role of this region in disease susceptibility. [ABSTRACT FROM AUTHOR]