Zhenzhen Wang

Variant Analysis of CARD14 in a Chinese Han Population with Psoriasis Vulgaris and Generalized Pustular Psoriasis

TO THE EDITOR n nPsoriasis is a common, chronic, inflammatory, organ-specific autoimmune skin disease with a complex genetic background (Nestle et al., 2009; Zhang et al., 2013). Psoriasis vulgaris (PsV) is the most common type, accounting for approximately 85–90% of all psoriasis patients, and characterized by raised, well-demarcated, erythematous oval plaques with adherent silvery scales (Nestle et al., 2009). Generalized pustular psoriasis (GPP) is the least prevalent form of psoriasis and is considered to be a potentially life-threatening, multi-systemic disease (Korber et al., 2013), characterized by the sudden eruption of generalized sterile pustules in a wave-like manner (Mengesha and Bennett, 2002). n nGenetic factors have been shown to have a critical role in the pathogenesis of psoriasis, and several genes and genomic regions have been reportedly associated with some clinical forms of this disease (http://omim.org/), including the gene for caspase recruitment domain family member 14 (CARD14), which was identified by fine-mapping of psoriasis susceptibility locus 2 (PSORS2) in European and Taiwanese patients (Hwu et al., 2005; Jordan et al., 2012a). To date, 23 variants have been reported in the CARD14 gene (Supplementary Table S3 online), mainly in patients with PsV (Jordan et al., 2012a; 2012b; Korber et al., 2013). However, most studies of CARD14 have been carried out in European populations, and studies in Chinese patients are rare. n nWe performed direct DNA sequencing in 236 psoriasis patients (174 PsV and 62 GPP patients) and 365 controls to investigate the prevalence of CARD14 variants in the Chinese Han population. We also compared CARD14 variants between patients with GPP and PsV and between pediatric- and late-onset PsV. n nA total of four new, rare heterozygous missense variants (allele frequency G) and p.Arg166His (c.497G>A) were only seen in GPP with PsV patients, and p.Ala216Thr (c.646G>A) and p.Thr591Met (c.1772C>T) (rs200102454) were only seen in PsV patients. We predicted the effects of the four variants on protein function using the Sorting Intolerant From Tolerant (SIFT) tool (http://sift.bii.a-star.edu.sg). Only p.Thr591Met was predicted to have damaging effects (score=0.03), whereas the other three were predicted to be tolerated (Supplementary Table S4 and Supplementary Figure S1 online). n nAn additional known rare heterozygous variant p.Arg682Trp (c.2044C>T) (rs117918077), which was reported in 1.3% of 2169 European psoriasis patients (Jordan et al., 2012b), was only found in one GPP with PsV patient (0.2% in psoriasis patients) in this study (Supplementary Table S4 and Supplementary Figure S1 online). n nThe overall frequency of these five rare variants was 1.1% in psoriasis patients (0.6% in PsV patients and 2.4% in GPP patients) but 0% in controls. A significant association between CARD14 rare variants and GPP was observed using Fishers exact test (corrected-P=0.03), but there was no significant association with either psoriasis or PsV (corrected-P=0.09, 0.998, respectively). We also conducted a gene-burden test using the sequence kernel association test package to compare the distributions of the five rare missense variants in psoriasis patients and controls, which showed a P-value of 0.00172. Subtype analysis of PsV versus GPP and pediatric- versus late-onset PsV revealed no significant differences in the frequencies of the five rare variants (corrected-P=0.438, 1, respectively; Table 1). n n n nTable 1 n nAnalysis of five rare CARD14 variants using Fishers exact test n n n nOne known low-frequency variant, p.Asp176His (c.526G>C) (rs144475004), was detected with frequencies of 1.9% in psoriasis patients and 1.8% in controls. Three common single-nucleotide polymorphisms (SNPs), rs2066964, rs34367357, and rs11652075, were also detected in our samples, with frequencies of 44.1 vs. 7.4 vs. 44.3% in psoriasis patients and 46.0 vs. 5.6 vs. 48.2% in controls, respectively. There were no differences between the groups in terms of these four variants (Supplementary Table S5 and Supplementary Figure S1 online). n nCARD14 is located within PSORS2 and encodes a nuclear factor (NF)-κB activator. Variants in CARD14 have recently been detected in association with psoriasis, mostly in patients with PsV (Jordan et al., 2012b). Particular rare variants within CARD14 could lead to psoriasis by upregulating psoriasis-associated genes in keratinocytes (Jordan et al., 2012a). n nThe present study identified five rare variants that, in combination, were more common in psoriasis patients compared with controls. Regarding the predicted effects of these rare variants on protein function, p.Thr591Met and p.Arg682Trp were predicted to be damaging, possibly by regulating the activation of NF-κB, leading to inflammation and epidermal hyperplasia. The other variants were not predicted to be damaging, and their functions remain unknown. n nGPP is considered to differ from PsV in terms of its etiology, especially regarding variants in the IL36RN gene (Korber et al., 2013; Li et al., 2013; Sugiura et al., 2013). In our study, variants within CARD14 significantly associated with GPP, compared with controls. However, we failed to find any difference between GPP and PsV, which might be attributed to the insufficient sample size. To elucidate whether the gene CARD14 is a specific susceptibility gene for PsV or GPP, further study with a large sample size is needed. n nDifferent genes have been reported to be responsible for diseases with different onset ages (Swanbeck et al., 1995). Cheng et al. (2014) performed an association analysis in patients with early-onset psoriasis (onset age <40 years) and identified significant associations with the SNP rs4649203 in IL28RA and rs2303138 in LNPEP (rs4649203, P=0.0191, odds ratio (OR)=0.87; rs2303138, P=0.00391, OR=1.15). However, the current study failed to distinguish between pediatric- and late-onset PsV in terms of CARD14 variants. We therefore conclude that the CARD14 gene variant cannot explain age of onset in this cohort of psoriasis patients. n nIn conclusion, we performed an association analysis between CARD14 variants and psoriasis in a Chinese Han population. The results suggest that rare CARD14 variants may have an important role in the pathogenesis of GPP. n nThis study was approved by the human medical and ethics committee of Shandong Provincial Institute of Dermatology and Venereology and was conducted according to the Declaration of Helsinki Principles. After informed consent, genomic DNA was extracted from patients peripheral blood samples using a QuickGene DNA whole blood kit L (Kurabo Industries, Osaka, Japan). All exons of the CARD14 gene were amplified by PCR, and the products were sequenced on an ABI 3130xl Genetic Analyser (Applied Biosystems ABI, Carlsbad, CA). (For specific details about materials and methods see Supplementary Data online).

Mutation analysis of the IL36RN gene in Chinese patients with generalized pustular psoriasis with/without psoriasis vulgaris

BACKGROUNDnGeneralized pustular psoriasis (GPP) is a rare type of psoriasis with potentially life-threatening implications. Mutations in IL36RN gene have been suggested to be causative or predisposing factors for GPP.nnnOBJECTIVEnTo evaluate the genetic heterogeneity of GPP, PV and GPP alone, GPP with PV.nnnMETHODSnWe performed a sanger sequencing identify IL36RN mutations in 62 Chinese Han patients with sporadic GPP, including 17 GPP without psoriasis vulgaris (PV) (GPP alone) cases vs. 45 GPP with preceding, later or accompanied by PV (GPP with PV) cases; 16 patients with pediatric-onset GPP (PGPP) vs. 46 adult-onset GPP (AGPP). We included 96 healthy controls and 174 sporadic patients with PV.nnnRESUTSnWe found 2 new variants and 4 known IL36RN variants in 29 GPP patients, 18 individuals carried recessive (homozygous/compound heterozygous) alleles and 11 cases harbored a single heterozygous change. Twelve PV patients and six controls harbored a single heterozygous for three out of the six variants. Significant differences were observed between GPP and PV groups, GPP alone and GPP with PV groups when compared frequencies of IL36RN variants, but we did not found association between PGPP and AGPP groups.nnnCONCLUSIONnOur study provided more evidence that GPP and PV are distinct subtypes of psoriasis caused by different pathogenesis, and GPP alone could be regarded as an especial entities of GPP which is different from GPP with PV on the etiology.

Lack of association between the single nucleotide polymorphism of ST18 and pemphigus in Chinese population

(5.9%) in the LAMB3 gene are reported as recurrent mutations in Caucasian people, but these are absent in Japanese. p.Arg972* in LAMB3, as in our case, has been previously reported as a recurrent mutation in the worldwide population, but represents only 1.8% of the mutation database. In conclusion, we experienced a Japanese patient with Herlitz junctional EB who initially showed a few blisters on the limited area and identified a novel deletion mutation (c.647delA) in the LAMB3 gene. From his initial clinical features, at first, we suspected him of having dystrophic EB, but it was not until we examined antigen mapping that diagnosis of Herlitz junctional EB was confirmed. Therefore, we would emphasize the importance of antigen mapping study in all cases of EB, even if the initial lesion is mild.

Identification of PTPN22 ,ST6GAL1 and JAZF1 as psoriasis risk genes demonstrates shared pathogenesis between psoriasis and diabetes

The biological connections between psoriasis and diabetes have been suggested by epidemiological, immunological and genetic studies. To identify additional shared susceptibility loci and investigate shared pathogenesis between these two diseases, we genotyped 89 reported diabetes susceptibility loci in 4456 psoriasis cases and 6027 controls of Chinese population using the MassARRAY system from Sequenom. We discovered three significant associations at rs6679677 on 1p13.2 (P=6.15×10−5, OR=5.07), rs16861329 on 3q27.3 (P=2.02×10−4, OR=0.87) and rs849135 on 7p15.1 (P=6.59×10−9, OR=1.78), which suggested PTPN22, ST6GAL1 and JAZF1 as novel susceptibility genes for psoriasis in Chinese population. Our findings implicated the involvement of T‐cell receptor signalling pathway in the pathogenesis of psoriasis and further confirmed the shared genetic susceptibility between psoriasis and diabetes.

Prediction of leprosy in the Chinese population based on a weighted genetic risk score

Genome wide association studies (GWASs) have revealed multiple genetic variants associated with leprosy in the Chinese population. The aim of our study was to utilize the genetic variants to construct a risk prediction model through a weighted genetic risk score (GRS) in a Chinese set and to further assess the performance of the model in identifying higher-risk contact individuals in an independent set. The highest prediction accuracy, with an area under the curve (AUC) of 0.743 (95% confidence interval (CI): 0.729–0.757), was achieved with a GRS encompassing 25 GWAS variants in a discovery set that included 2,144 people affected by leprosy and 2,671 controls. Individuals in the high-risk group, based on genetic factors (GRS > 28.06), have a 24.65 higher odds ratio (OR) for developing leprosy relative to those in the low-risk group (GRS≤18.17). The model was then applied to a validation set consisting of 1,385 people affected by leprosy and 7,541 individuals in contact with leprosy, which yielded a discriminatory ability with an AUC of 0.707 (95% CI: 0.691–0.723). When a GRS cut-off value of 22.38 was selected with the optimal sensitivity and specificity, it was found that 39.31% of high risk contact individuals should be screened in order to detect leprosy in 64.9% of those people affected by leprosy. In summary, we developed and validated a risk model for the prediction of leprosy that showed good discrimination capabilities, which may help physicians in the identification of patients coming into contact with leprosy and are at a higher-risk of developing this condition.

Comparison of fungal fluorescent staining and ITS rDNA PCR‐based sequencing with conventional methods for the diagnosis of onychomycosis

The current gold standard for diagnosing onychomycosis is direct microscopic examination and culturing. Fungal culture is a time‐consuming procedure, while direct microscopy of potassium hydroxide (KOH) mounts suffers from low sensitivity. More rapid and sensitive methods for the diagnosis of onychomycosis are in high demand.

Association analysis of the genetic polymorphisms with leprosy subtypes in Chinese Han population from Northern China

Leprosy is characterized by a broad spectrum of clinical manifestations that extend from paucibacillary (PB) to multibacillary (MB) depending upon the different immunologic response to the invading of M. leprae 3,4 . It has been widely accepted that genetic predisposition plays the crucial role in the different clinical manifestations. Host susceptibility to leprosy is modified by number of genes via two stages. In the first stage, a group of genes confers susceptibility to leprosy per se; A second group of genes are associated to the type of host immune response and leprosy subtype5 . This article is protected by copyright. All rights reserved.

A pathway‐based association analysis identified FMNL1‐MAP3K14 as susceptibility genes for leprosy

The nuclear transcription factor‐κB (NF‐κB) plays a pivotal role in controlling both innate and adaptive immunity and regulates the expressions of many immunological mediators. Abundant evidences have showed the importance of NF‐κB pathway in the host immune responses against Mycobacterium leprae in the development of leprosy. However, no particular association study between leprosy and NF‐κB pathway‐related gene polymorphisms was reported. Here, we performed a large‐scale and two‐stage candidate association study to investigate the association between 94 NF‐κB pathway‐related genes and leprosy. Our results showed that rs58744688 was significantly associated with leprosy (P = 7.57 × 10−7, OR = 1.12) by combining the previous genomewide association data sets and four independent validation sample series, consisting of a total of 4631 leprosy cases and 6413 healthy controls. This founding implicated that MAP3K14 and FMNL1 were susceptibility genes for leprosy, which suggested the involvement of macrophage targeting and NF‐κB pathway in the development of leprosy.

Amino acid variants of HLA-DRB1 confer susceptibility to dapsone hypersensitivity syndrome in addition to HLA-B*13:01

Dapsone hypersensitivity syndrome is a rare yet severe adverse drug reaction caused by dapsone, a principal drug in multidrug therapy for leprosy. HLA-B*13:01 has been identified as a strong risk factor of dapsone hypersensitivity syndrome; however, its low positive predictive value indicated that additional genetic variants may be involved in the disease development. To discover contributing genetic variants within HLA loci in addition to HLA-B*13:01, we performed a high-coverage next-generation sequencing (NGS)-based HLA typing analysis in 103 dapsone-hypersensitive and 857 dapsone-tolerant HLA-B*13:01-positive leprosy patients in a Chinese population. Five amino acid variants in high linkage disequilibrium of HLA-DRB1 were significantly associated with dapsone hypersensitivity syndrome (positions 133, 142, -17, 11, and 13). DRB1*16:02 and DRB1*15:01 tagged by these risk-conferring amino acid residues were associated at a nominal significance level. This study identifies five amino acid variants within HLA-DRB1 that are in high linkage disequilibrium and significantly associated with dapsone hypersensitivity syndrome in a Chinese population.