Yuyan Cheng

Whole-exome SNP array identifies 15 new susceptibility loci for psoriasis

Genome-wide association studies (GWASs) have reproducibly associated ∼40 susceptibility loci with psoriasis. However, the missing heritability is evident and the contributions of coding variants have not yet been systematically evaluated. Here, we present a large-scale whole-exome array analysis for psoriasis consisting of 42,760 individuals. We discover 16 SNPs within 15 new genes/loci associated with psoriasis, including C1orf141, ZNF683, TMC6, AIM2, IL1RL1, CASR, SON, ZFYVE16, MTHFR, CCDC129, ZNF143, AP5B1, SYNE2, IFNGR2 and 3q26.2-q27 (P<5.00 × 10−08). In addition, we also replicate four known susceptibility loci TNIP1, NFKBIA, IL12B and LCE3D–LCE3E. These susceptibility variants identified in the current study collectively account for 1.9% of the psoriasis heritability. The variant within AIM2 is predicted to impact protein structure. Our findings increase the number of genetic risk factors for psoriasis and highlight new and plausible biological pathways in psoriasis.

Association between the PD1.3A/G polymorphism of the PDCD1 gene and systemic lupus erythematosus in European populations: a meta-analysis

Background  Linkage studies suggest a locus, SLEB2, involved in susceptibility to systemic lupus erythematosus (SLE) and programmed cell death 1 (PDCD1) gene locates in this region. The association of PDCD1 polymorphism (PD1.3A/G) with SLE has been widely investigated, but there are no unambiguous conclusions.

Epigenome-wide association data implicates DNA methylation-mediated genetic risk in psoriasis

BackgroundPsoriasis is a chronic inflammatory skin disease characterized by epidermal hyperproliferation and altered keratinocyte differentiation and inflammation and is caused by the interplay of genetic and environmental factors. Previous studies have revealed that DNA methylation (DNAm) and genetic makers are closely associated with psoriasis, and strong evidences have shown that DNAm can be controlled by genetic factors, which attracted us to evaluate the relationship among DNAm, genetic makers, and disease status.MethodsWe utilized the genome-wide methylation data of psoriatic skin (PP, N = 114) and unaffected control skin (NN, N = 62) tissue samples in our previous study, and we performed whole-genome genotyping with peripheral blood of the same samples to evaluate the underlying genetic effect on skin DNA methylation. Causal inference test (CIT) was used to assess whether DNAm regulate genetic variation and gain a better understanding of the epigenetic basis of psoriasis susceptibility.ResultsWe identified 129 SNP-CpG pairs achieving the significant association threshold, which constituted 28 unique methylation quantitative trait loci (MethQTL) and 34 unique CpGs. There are 18 SNPs were associated with psoriasis at a Bonferoni-corrected P < 0.05, and these 18 SNPs formed 93 SNP-CpG pairs with 17 unique CpG sites. We found that 11 of 93 SNP-CpG pairs, composed of 5 unique SNPs and 3 CpG sites, presented a methylation-mediated relationship between SNPs and psoriasis. The 3 CpG sites were located on the body of C1orf106, the TSS1500 promoter region of DMBX1 and the body of SIK3.ConclusionsThis study revealed that DNAm of some genes can be controlled by genetic factors and also mediate risk variation for psoriasis in Chinese Han population and provided novel molecular insights into the pathogenesis of psoriasis.

Discovery of a novel genetic susceptibility locus on X chromosome for systemic lupus erythematosus.

IntroductionSystemic lupus erythematosus (SLE) is an autoimmune connective tissue disease affecting predominantly females. To discover additional genetic risk variants for SLE on the X chromosome, we performed a follow-up study of our previously published genome-wide association study (GWAS) data set in this study.MethodsTwelve single nucleotide polymorphisms (SNPs) within novel or unpublished loci with P-value < 1.00 × 10−02 were selected for genotype with a total of 2,442 cases and 2,798 controls(including 1,156 cases and 2,330 controls from central China, 1,012 cases and 335 controls from southern China and 274 cases and 133 controls from northern China) using Sequenom Massarry system. Associaton analyses were performed using logistic regression with sample region as a covariate through PLINK 1.07 software.ResultsCombined analysis in discovery and central validation dataset discovered a novel locus rs5914778 within LINC01420 associated with SLE at genome-wide significance (P = 1.00 × 10−08; odds ratio (OR) = 1.32). We also confirmed rs5914778 in the southern Chinese sample cohort (P = 5.31 × 10−05; OR = 1.51), and meta-analysis of the samples from the discovery, central and southern validations regions provided robust evidence for the association of rs5914778 (P = 5.26 × 10−12; OR = 1.35). However, this SNP did not show association with SLE in the northern sample (P = 0.33). Further analysis represent the association of northern was significantly heterogeneous compared to central and southern respectively.ConclusionsOur study increases the number of established susceptibility loci for SLE in Han Chinese population and has further demonstrated the important role of X-linked genetic risk variants in the pathogenesis of SLE in Chinese Han population.

More heritability probably captured by psoriasis genome-wide association study in Han Chinese

Missing heritability is a common problem in genome-wide association studies in complex diseases/traits. To quantify the unbiased heritability estimate, we applied the phenotype correlation-genotype correlation regression in psoriasis genome-wide association data in Han Chinese which comprises 1139 cases and 1132 controls. We estimated that 45.7% heritability of psoriasis in Han Chinese were captured by common variants (s.e.=12.5%), which reinforced that the majority of psoriasis heritability can be covered by common variants in genome-wide association data (68.2%). The results provided evidence that the heritability covered by psoriasis genome-wide genotyping data was probably underestimated in previous restricted maximum likelihood method. Our study highlights the broad role of common variants in the etiology of psoriasis and sheds light on the possibility to identify more common variants of small effect by increasing the sample size in psoriasis genome-wide association studies.

Exome-wide association study identifies four novel loci for systemic lupus erythematosus in Han Chinese population

Objectives Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of considerable genetic predisposition. Genome-wide association studies have identified tens of common variants for SLE. However, the majority of them reside in non-coding sequences. The contributions of coding variants have not yet been systematically evaluated. Methods We performed a large-scale exome-wide study in 5004 SLE cases and 8179 healthy controls in a Han Chinese population using a custom exome array, and then genotyped 32 variants with suggestive evidence in an independent cohort of 13 246 samples. We further explored the regulatory effect of one novel non-coding single nucleotide polymorphism (SNP) in ex vivo experiments. Results We discovered four novel SLE gene regions (LCT, TPCN2, AHNAK2 and TNFRSF13B) encompassing three novel missense variants (XP_016859577.1:p.Asn1639Ser, XP_016859577.1:p.Val219Phe and XP_005267356.1:p.Thr4664Ala) and two non-coding variants (rs10750836 and rs4792801) with genome-wide significance (pmeta <5.00×10−8). These variants are enriched in several chromatin states of primary B cells. The novel intergenic variant rs10750836 exhibited an expression quantitative trait locus effect on the TPCN2 gene in immune cells. Clones containing this novel SNP exhibited gene promoter activity for TPCN2 (P=1.38×10−3) whose expression level was reduced significantly in patients with SLE (P<2.53×10−2) and was suggested to be further modulated by rs10750836 in CD19+ B cells (P=7.57×10−5) in ex vivo experiments. Conclusions This study identified three novel coding variants and four new susceptibility gene regions for SLE. The results provide insights into the biological mechanism of SLE.

Downregulated expression of LBH mRNA in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

We performed a gene expression study to explore whether expression levels of LBH contribute to the pathogenesis of systemic lupus erythematosus (SLE) and are associated with the genome‐wide association study‐identified SNP (rs7579944 and rs906868) and the SLE Disease Activity Index (SLEDAI). Fluorescent quantitative reverse transcription polymerase chain reaction was used to examine the expression of LBH mRNA in peripheral blood mononuclear cells (PBMC) from 62 SLE patients and 69 controls. The expression levels of LBH mRNA in patients with SLE were significantly decreased compared with those in normal controls (P < 0.001). No significant differences were found between LBH mRNA expression levels and SLEDAI scores, SNP rs7579944 and rs906868. This study suggests that decreased expression of LBH mRNA may be correlated with the pathogenesis of SLE.

Author Correction: Whole-exome SNP array identifies 15 new susceptibility loci for psoriasis

This corrects the article DOI: 10.1038/ncomms7793.

Novel compound heterozygous variants in the XPC gene identified in a Chinese xeroderma pigmentosum group C patient with ovarian teratoma

Ying DENG, Dengmei XIA, Lian WANG, Mengmeng LI, Wei LI National Office for Maternal and Child Health Surveillance of China, Department of Pediatrics, West China Second University Hospital, Laboratory of Molecular Epidemiology for Birth Defect, West China Institute of Women and Children’s Health, Sichuan University, Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Department of Dermatology, Southwest Medical University Affiliated Hospital, Luzhou, and Department of Dermatology, The West China Hospital, Sichuan University, Chengdu, China

Novel mutations in Chinese Han patients with tuberous sclerosis complex: Case series and review of the published work

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disease characterized by hamartomas in multiple organ systems. This study was performed in one familial and two sporadic cases with TSC. Two novel mutations (c.1884_1887delAAAG and c.5266A>G) and two previously reported mutations (c.4258_4261delTCAG and c.1960G>C) were identified by direct DNA sequencing. Of the four mutations, c.1884_1887delAAAG and c.1960G>C were found in a family and identified in the same allele by TA cloning sequencing. However, c.1960G>C was reported to be non‐pathogenic. Furthermore, correlations between genotypes and phenotypes of Chinese Han patients since 2014 were performed by paired χ2‐tests in our published work review, which has not been reported. The results showed that patients with TSC2 mutations had a higher frequency of mental retardation and there were no significant differences of seizures and skin lesions with TSC1 mutations. Genetically, they had a higher frequency of familial inheritance.