[Genetic analysis of a child with Hypotrichosis simplex].

OBJECTIVE: To explore the clinical phenotype and genetic characteristics of a child with Hypotrichosis 14. METHODS: A child who had presented at the Henan Provincial People's Hospital on May 4, 2020 due to hair thinning was selected as the study subject. Clinical data of the child was collected. Peripheral venous blood samples were collected from the child and her parents. Genomic DNA was extracted and subjected to whole exome sequencing. Candidate variants were validated by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 5-year-old female, had presented with thin, soft lanugo-like hair which was easy to fall off. The child was found to harbor compound heterozygous missense variants of the LSS gene, namely c.1609G>A (p.V537M) in exon 17 and c.802T>G (p.F268V) in exon 8, which were respectively inherited from her father and mother. Both variant sites were highly conserved, though based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as variants of unknown significance (PM2_Supporting+PP3+PP4). CONCLUSION: The c.1609G>A (p.V537M) and c.802T>G (p.F268V) compound heterozygous variants of the LSS gene probably underlay the clinical phenotype in this patient.

Shikonin potentiates skin wound healing in Sprague-Dawley rats by stimulating fibroblast and endothelial cell proliferation and angiogenesis.

BACKGROUND: Shikonin, a major component of Lithospermum erythrorhizon, exerts anti-inflammatory and antibacterial effects and expedites wound healing. This study aims to evaluate the anti-inflammatory and antioxidant activities of shikonin in a Sprague-Dawley rat model and cell models using fibroblast and endothelial cells. METHODS: The impact of shikonin on the activity of endothelial cells and fibroblasts was examined by cell counting kit 8 and wound-healing assays. A diabetic rat model was constructed, followed by wound creation for treatment with shikonin. Hematoxylin-eosin staining was used to assess pathological changes, and Masson's trichrome method to detect collagen deposition. Immunohistochemistry using antibodies against proliferating cell nuclear antigen and CD31 was conducted to detect proliferation and vascular density. Enzyme-linked immunosorbent assay and immunohistochemistry were carried out to assess pro-inflammatory and anti-inflammatory factor concentrations. Western blot and immunofluorescence were implemented to analyze oxidative stress-related protein expression. RESULTS: Shikonin induced the activity of both fibroblasts and endothelial cells. Shikonin treatment contributed to facilitated wound healing and higher healing rates in rats. It also resulted in faster lesion debulking in tissues, reduced inflammatory infiltration, increased collagen deposition, and enhanced angiogenesis. Detection of markers at the wounds showed that shikonin accelerated cell proliferation, enhanced tissue remodeling, and inhibited oxidative stress. CONCLUSION: Shikonin stimulates the proliferation and migration of fibroblasts and endothelial cells to promote angiogenesis and tissue remodeling, resulting in faster wound healing.

Haplotype-based non-invasive prenatal diagnosis of recessive dystrophic epidermolysis bullosa via targeted capture sequencing of maternal plasma.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare and severe hereditary skin disease, caused by mutations in the COL7A1. However, whether non-invasive prenatal testing (NIPT) can be used for this monogenic genodermatosis remains unknown. Accordingly, we conducted a study in which one couple at high risk of having a fetus with RDEB were recruited and tested by haplotyping-based NIPT. Next-generation sequencing-based multi-gene panel testing was carried out in this couple and their first child as proband who was affected with RDEB. We deduced parental haplotypes via single nucleotide polymorphism (SNP)-based haplotype linkage analysis. Then the maternal plasma cell-free DNA was also sequenced to determine the fetal haplotypes using a parental haplotype-assisted hidden Markov model (HMM) analysis. Results show that the fetus was only a heterozygous mutation carrier in COL7A1 and the identical results were obtained after birth. These results demonstrate that haplotyping-based NIPT is a feasible method for NIPT of RDEB.

[Variation of COL7A1 gene in dystrophic epidermolysis bullosa pruriginosa].

OBJECTIVE: To perform gene mutation analysis in a Chinese pedigree with dystrophic epidermolysis bullosa pruriginosa (DEB-Pr), and explore phetotype, genotype, and genotypes-phenotypes relationship of DEB-Pr. METHODS: Potential variants of the COL7A1 gene were detected by skin targeted sequencing panel and verified by Sanger sequencing. The pathogenicity of the variation was analyzed. RESULTS: Compound heterozygous variants, c.4128delT and c.8234G>A, were detected in the COL7A1 gene of the two patients. The c.4128delT(p.Pro1376fs) variant was derived from their mother and unreported previously. According to the American College of Medical Genetics and Genomics Standards and Guidelines, it was suggested to be a pathogenic mutation. The c.8234G>A(p.Arg2745Gln) variant was derived from their father, and possibly is a pathogenic variation. CONCLUSION: In this study, the compound heterozygous variants of c.4128delT(p.Pro1376fs) and c.8234G>A(p.Arg2745Gln) of the COL7A1 gene probably underlies the disease in this patient and his sister. And our study expands the database on mutations of DEB-Pr.

[Genetic testing and genotype-phenotype analysis for a child with X-linked hypohidrotic ectodermal dysplasia].

OBJECTIVE: To carry out genetic testing for a Chinese patient with X-linked hypohidrotic ectodermal dysplasia (XLHED) and explore its genotype-phenotype correlation. METHODS: Clinical data of the patient was collected. Peripheral blood samples were taken from the patient, his parents and 100 unrelated healthy controls. Genetic variants were detected by using next-generation sequencing using a skin-disease panel through targeted capture and next generation sequencing. Candidate variant was verified by Sanger sequencing. All literature related to genetic testing of XLHED patients in China was searched in the database, and the genotypes and phenotypes of patients in the literature and the correlation between them were statistically analyzed. RESULTS: A novel splice site variant c.655_689del was detected in the patient but not among his parents and the 100 unrelated healthy controls. So far 61 variants of the EDA gene have been identified among Chinese patients with XLHED, which suggested certain degree of genotype-phenotype correlation. CONCLUSION: A novel c.655_689del variant has been identified in the EDA gene, which has expanded the spectrum of EDA gene variant and facilitated delineation of the genotype-phenotype correlation of XLHED.

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.

DNA methylation-based subclassification of psoriasis in the Chinese Han population.

Psoriasis (Ps) is an inflammatory skin disease caused by genetic and environmental factors. Previous studies on DNA methylation (DNAm) found genetic markers that are closely associated with Ps, and evidence has shown that DNAm mediates genetic risk in Ps. In this study, Consensus Clustering was used to analyze DNAm data, and 114 Ps patients were divided into three subclassifications. Investigation of the clinical characteristics and copy number variations (CNVs) of DEFB4, IL22, and LCE3C in the three subclassifications revealed no significant differences in gender ratio and in Ps area and severity index (PASI) score. The proportion of late-onset ( ≥ 40 years) Ps patients was significantly higher in type I than in types II and III (P = 0.035). Type III contained the smallest proportion of smokers and the largest proportion of non-smoking Ps patients (P = 0.086). The CNVs of DEFB4 and LCE3C showed no significant differences but the CNV of IL22 significantly differed among the three subclassifications (P = 0.044). This study is the first to profile Ps subclassifications based on DNAm data in the Chinese Han population. These results are useful in the treatment and management of Ps from the molecular and genetic perspectives.

Genotype combination contributes to psoriasis: An exhaustive algorithm perspective.

Researchers have learned that nearly all conditions and diseases have a genetic component. With the benefit of technological advances, many single-nucleotide polymorphisms (SNPs) have been found to be associated with the risk of complex disorders by using genome wide association studies (GWASs). Disease-associated SNPs are sometimes shared by healthy controls and cannot clearly distinguish affected individuals from unaffected ones. The combined effects of multiple independent SNPs contribute to the disease process, but revealing the relationship between genotype and phenotype based on the combinations remains a great challenge. In this study, by considering the disease prevalence rate, we conducted an exhaustive process to identify whether a genotype combination pattern would have a decisive effect on complex disorders. Based on genotype data for 68 reported SNPs in 8,372 psoriasis patients and 8,510 healthy controls, we found that putative causal genotype combination patterns (CGCPs) were only present in psoriasis patients, not in healthy subjects. These results suggested that psoriasis might be contributed by combined genotypes, complementing the traditional modest susceptibility of a single variant in a single gene for a complex disease. This work is the first systematic study to analyze genotype combinations based on the reported susceptibility genes, considering each individual among the cases and controls from the Chinese population, and could potentially advance disease-gene mapping and precision medicine due to the causality relationship between the candidate CGCPs and complex diseases.

Genetic factors are stressed variably by onset age-based sample selection in psoriasis: A hint from major histocompatibility complex region-based analysis.

BACKGROUND: Large cohort-based genetic association studies have been established over a decade. However, for certain diseases, different results with respect to the genome-wide association study level have been obtained among studies, even for those conducted within the same ethnic groups. We hypothesized that onset age-based sample variables might have a great impact on the results. METHODS: In the present study, we divided psoriasis patients into several subgroups according to the onset age bracket. We conducted genetic association analysis in the major histocompatibility complex (MHC) region of each patient subgroup with shared control subjects. RESULTS: We found decreases in the numbers of susceptible variants in each subgroup analysis as the onset age increased in the longitudinal analysis. Meanwhile, the pairwise analysis showed that younger patients exhibited greater numbers of genetic risks in the MHC region compared to elder patients, regardless of whether the cut-off values were defined as 20 or 30 years old. Similar results were also found among 11-20-, 21-30- and 31-40-year-old groups. Furthermore, when combining the results of both the stepwise regression analysis and the HLA-C*06:02 conditioning analysis, different variants were found to be independently associated with each psoriasis subgroup. CONCLUSIONS: Onset age-based sample variables influence the results of genetic association studies, at least in MHC region-based genetic analysis. We suggest that caution is required when selecting samples for genetic association studies to prevent confounders that might be a result of onset age.

An in-depth analysis identifies two new independent signals in 11q23.3 associated with vitiligo in the Chinese Han population.

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.

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

BACKGROUND: Psoriasis 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. METHODS: We 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. RESULTS: We 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. CONCLUSIONS: This 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.

A rare variant in COL11A1 is strongly associated with adult height in Chinese Han population.

Human height is a highly heritable trait in which multiple genes are involved. Recent genome-wide association studies (GWASs) have identified that COL11A1 is an important susceptibility gene for human height. To determine whether the variants of COL11A1 are associated with adult and children height, we analyzed splicing and coding single-nucleotide variants across COL11A1 through exome-targeted sequencing and two validation stages with a total 20,426 Chinese Han samples. A total of 105 variants were identified by exome-targeted sequencing, of which 30 SNPs were located in coding region. The strongest association signal was Chr1_103380393 with P value of 4.8 × 10(-7). Chr1_103380393 also showed nominal significance in the validation stage (P = 1.21 × 10(-6)). Combined analysis of 16,738 samples strengthened the original association of chr1_103380393 with adult height (Pcombined = 3.1 × 10(-8)), with an increased height of 0.292sd (standard deviation) per G allele (95% CI: 0.19-0.40). There was no evidence (P = 0.843) showing that chr1_103380393 altered child height in 3688 child samples. Only the group of 12-15 years showed slight significance with P value of 0.0258. This study firstly shows that genetic variants of COL11A1 contribute to adult height in Chinese Han population but not to children height, which expand our knowledge of the genetic factors underlying height variation and the biological regulation of human height.

Genetic Susceptibility to Vitiligo: GWAS Approaches for Identifying Vitiligo Susceptibility Genes and Loci.

Vitiligo is an autoimmune disease with a strong genetic component, characterized by areas of depigmented skin resulting from loss of epidermal melanocytes. Genetic factors are known to play key roles in vitiligo through discoveries in association studies and family studies. Previously, vitiligo susceptibility genes were mainly revealed through linkage analysis and candidate gene studies. Recently, our understanding of the genetic basis of vitiligo has been rapidly advancing through genome-wide association study (GWAS). More than 40 robust susceptible loci have been identified and confirmed to be associated with vitiligo by using GWAS. Most of these associated genes participate in important pathways involved in the pathogenesis of vitiligo. Many susceptible loci with unknown functions in the pathogenesis of vitiligo have also been identified, indicating that additional molecular mechanisms may contribute to the risk of developing vitiligo. In this review, we summarize the key loci that are of genome-wide significance, which have been shown to influence vitiligo risk. These genetic loci may help build the foundation for genetic diagnosis and personalize treatment for patients with vitiligo in the future. However, substantial additional studies, including gene-targeted and functional studies, are required to confirm the causality of the genetic variants and their biological relevance in the development of vitiligo.

Knockdown of asparagine synthetase by RNAi suppresses cell growth in human melanoma cells and epidermoid carcinoma cells.

Melanoma, the most aggressive form of skin cancer, causes more than 40,000 deaths each year worldwide. And epidermoid carcinoma is another major form of skin cancer, which could be studied together with melanoma in several aspects. Asparagine synthetase (ASNS) gene encodes an enzyme that catalyzes the glutamine- and ATP-dependent conversion of aspartic acid to asparagine, and its expression is associated with the chemotherapy resistance and prognosis in several human cancers. The present study aims to explore the potential role of ASNS in melanoma cells A375 and human epidermoid carcinoma cell line A431. We applied a lentivirus-mediated RNA interference (RNAi) system to study its function in cell growth of both cells. The results revealed that inhibition of ASNS expression by RNAi significantly suppressed the growth of melanoma cells and epidermoid carcinoma cells, and induced a G0/G1 cell cycle arrest in melanoma cells. Knockdown of ASNS in A375 cells remarkably downregulated the expression levels of CDK4, CDK6, and Cyclin D1, and upregulated the expression of p21. Therefore, our study provides evidence that ASNS may represent a potential therapeutic target for the treatment of melanoma.