Investigation of the eotaxin gene -426C-->T, -384A-->G and 67G-->a single-nucleotide polymorphisms and atopic dermatitis in Italian children using family-based association methods.

BACKGROUND: Eotaxin plays an important role in atopic dermatitis (AD) as a potent chemoattractant and activator of eosinophils and T-helper 2 lymphocytes. AIM: To investigate whether single-nucleotide polymorphisms of the eotaxin gene are associated with AD, we investigated the genotype and allelic frequencies of -426C-->T, -384A-->G, and 67G-->A SNPs in 130 Italian families. METHODS: In total, 130 children with either the extrinsic allergic or intrinsic nonallergic forms of AD (EAD and IAD) were recruited from 130 families. Genotyping was performed using PCR and restriction fragment length polymorphism analysis. RESULTS: A significant difference was observed in the genotype frequency of the -426C-->T SNP between children with EAD and those with IAD (P = 0.01), and between children with EAD and controls (P = 0.01). The allele frequencies of the -426C-->T SNP were significantly different between children with EAD and those with IAD (P < 0.01), and between children with EAD and controls (P < 0.01). For children with EAD, the genotype frequency of the -426C-->T SNP was no different between the groups with mild, moderate and severe SCORAD (P = NS). No significant association was observed between the -384A-->G and 67G-->A SNPs and the two groups of children with EAD and IAD compared with the control group. In 32 trios selected from 68 EAD families, the transmission disequilibrium test showed a preferential transmission of the -426T allele from the parents to affected offspring (P < 0.01). CONCLUSIONS: Our results suggest that in our group of children with AD, the eotaxin gene may play a crucial role in the development of extrinsic AD, probably with other genetic factors.     

The -431C>T polymorphism of thymus and activation-regulated chemokine increases the promoter activity but is not associated with susceptibility to atopic dermatitis in Japanese patients

BACKGROUND: Thymus and activation-regulated chemokine (TARC) plays an important role in the pathogenesis of atopic dermatitis (AD). We recently detected the single nucleotide polymorphism (SNP) (-431C>T) in the 5'-flanking region of TARC gene. OBJECTIVES: To examine whether the -431C>T SNP of the TARC gene is associated with susceptibility to AD and whether it affects the promoter activity of the TARC gene. METHODS: We investigated the genotype and allele frequencies of the SNP in 193 AD patients and 158 healthy controls by polymerase chain reaction-restriction fragment length polymorphism method. We compared the promoter activities between TARC promoter carrying 431C and that carrying -431T by transient-transfection assay in DJM-1 cell line. RESULTS: There were no significant differences in genotype or allele frequencies between AD patients and controls (genotype: P = 0.38, allele: P = 0.22). Luciferase activity was higher in -431T constructs than in -431C constructs (2.3-fold, P = 9.5 x 10(-6)). CONCLUSION: These results suggest that the -431C>T SNP of the TARC gene enhances the promoter activity of TARC gene but is not associated with susceptibility to AD in Japanese population.     

Interleukin-13 gene polymorphism G4257A is associated with atopic dermatitis in Japanese patients

Interleukin (IL)-13 plays an important role in the induction of immunoglobulin E (IgE) and in the pathogenesis of atopic dermatitis (AD). We investigated the allele and genotype frequencies of three IL-13 single nucleotide polymorphisms (SNPs) (A704C and C1103T in the promoter region and G4257A in exon 4) in Japanese patients with AD. For A704C and C1103T SNPs, there were no significant differences in allele or genotype frequencies between AD patients and controls. For G4257A SNP, A allele was significantly increased in AD patients (39.5%) compared with controls (29.4%) (P = 0.016). The same proportion of each genotype and allele was observed in the patient subgroup with and without asthma. Serum IgE levels and peripheral eosinophil counts were not significantly different among genotypes in G4257A SNP. There was also no significant difference in allele or genotype frequencies between AD patients with mild disease and those with severe disease, between those with family history of AD and those without it, or between those with family history of atopic disorders and those without it. This result suggests that 4257A allele is associated with susceptibility to AD and that it may function in the pathogenesis of AD itself, presumably by other mechanisms than inducing IgE production.     

An association between IL-9 and IL-9 receptor gene polymorphisms and atopic dermatitis in a Korean population

Background

The genes encoding IL-9 and IL-9R have recently been implicated in the genetic basis of asthma and allergy. Although studies performed on transgenic and knockout mice have shown conflicting results, no evidence of skin changes has ever been reported in these animals.

Objective

To find association of the SNPs in IL-9 and IL-9R genes and interaction of these genes in atopic dermatitis.

Method

We genotyped 5 SNPs from the IL-9 and IL-9R genes of 1090 subject samples (631 AD patients and 459 normal controls). A luciferase assay was then performed for the rs31563 (−4091G/A) SNP located in the IL-9 gene promoter region.

Result

The rs31563 (−4091G/A) SNP in the IL-9 gene was significantly associated with the AD phenotype, especially allergic-type AD. In the luciferase assay, the rs31563 G construct was observed to have 1.54 times higher activity than the rs31563 A construct. Although no association was found between SNPs in IL-9R gene and AD, the rs3093467 SNP showed association with non-allergic AD. In the gene-gene interaction analysis, we found that IL-9/IL-9R genotype rs31563 GG/rs3093467 TT conveyed a greater risk for AD phenotype development.

Conclusion

Significant evidence exists to suggest that the rs31563 SNP (−4091G/A) located in the IL-9 gene is associated with an increased susceptibility to AD. Similarly, the rs3093467 SNP in IL-9R gene seems to be associated with an increased risk for developing non-allergic AD. In a subsequent gene-gene interaction analysis, the rs31563 GG/rs3093467 TT genotype combination (IL-9/IL-9R) was found to exert a synergistic effect in the development of the AD phenotype. As the classes of helper T cells are diverse and the function of IL-9 cytokine has not been fully described, the cutaneous function of IL-9 needs to be further explored in future studies.     

Interleukin-12 p40 gene (IL12B) 3'-untranslated region polymorphism is associated with susceptibility to atopic dermatitis and psoriasis vulgaris

Interleukin-12 (IL-12) is believed to play an important role in inducing Th1-type cytokine profiles. Atopic dermatitis (AD) and psoriasis vulgaris (PsV) are considered to be Th2 and Th1 type disease, respectively. The IL-12 p40 subunit gene (IL12B) is located at chromosome 5q31-33 and linkage findings of AD on 5q31 were reported. Recently single nucleotide polymorphism (SNP) (1188A/C) of IL12B has been reported. In function, it has been reported that this SNP is associated with IL12B mRNA expression levels. To learn whether this SNP is associated with susceptibility to AD or PsV, we investigated the genotype and allele frequencies of the SNP in AD patients, in PsV patients and in controls, examining 164 AD patients, 143 PsV patients and 100 healthy individuals in Japanese population. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. The A allele was decreased in AD patients (40.9%, p = 0.031) and increased in PsV patients (60.1%, p = 0.035) compared with controls (50.5%). This suggests that IL12B SNP is associated with susceptibility to AD and PsV, presumably by affecting the Th1/Th2 balance.     

Lack of association between the promoter polymorphisms at positions -308 and -238 of the tumor necrosis factor alpha gene and psoriasis vulgaris in Japanese patients

BACKGROUND: Psoriasis features an increased level and activity of tumor necrosis factor alpha (TNF-alpha). The TNF-alpha gene has single nucleotide polymorphisms (SNPs) at positions -308 (-308G>A) and -238 (-238G>A) in the promoter region, and the -238G>A SNP has been reported to be associated with psoriasis vulgaris (PV) and psoriatic arthritis in Caucasians. OBJECTIVE: To examine whether these SNPs are associated with susceptibility to PV in Japanese patients, we investigated the genotype and allele frequencies at each SNP in Japanese PV patients and in controls. METHODS: We examined 163 PV patients and 96 healthy individuals. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: No significant association between the genotypes or alleles of these SNPs and susceptibility to PV was observed. CONCLUSION: These SNPs themselves are not associated with susceptibility to PV in the Japanese.     

儿童特应性皮炎IL-18基因启动子多态性与相关性研究

目的 检测儿童特应性皮炎患者外周血DNA中IL-18基因第2外显子上游启动子1第137和第607位点多态性，探讨其与儿童特应性皮炎发病的相关性。方法 从82例重庆汉族儿童特应性皮炎患者及健康对照组100例的抗凝血中提取DNA，用序列特异性引物PCR扩增技术（PCR-SSP）及PCR产物直接测序法鉴定基因类型，对结果进行统计学分析处理。结果 IL-18基因第2外显子的第137位点核苷酸存在G、C二态性，可表现为GG纯合、CC纯合、GC杂合三种基因型；第607位点核苷酸存在C、A二态性，可表现为CC纯合、AA纯合、CA杂合三种基因型。IL-18-137G/C基因型分布在患者组和对照组间差异有统计学意义，患者组137C等位基因频率显著高于对照组（χ2 = 4.54，P = 0.033），137C等位基因在重度组中分布频率显著高于轻度组（χ2 = 3.93，P < 0.05）；IL-18-607位点等位基因频率在轻度、中度、重度组及对照组之间分布差异无统计学意义（P > 0.05）；IL-18-137G/C位点C等位基因在病例与对照组比较，优势比OR = 1.76，137G/C基因型的优势比OR = 2.33。结论 儿童IL-18基因第2外显子上游启动子1第137和第607位点存在单核苷酸多态性，IL-18-137G/C是特应性皮炎患儿的候选易感基因。     

Association of SPINK5 gene polymorphisms with atopic dermatitis in Northeast China

Background Defect in the SPINK5 gene is known to be implicated in Netherton syndrome (NS), and has been suggested to be a locus predisposing to atopy in general. Coding polymorphisms in SPINK5 exons 13, 14 and 26 have been reported to be associated with atopic dermatitis (AD), asthma and high level of IgE. Objectives To examine whether the SPINK5 gene polymorphisms are associated with AD in Northeast China, and to assess how variants influence selected phenotypic traits. Methods A case–control study was conducted on four non‐synonymous polymorphisms in the coding region of SPINK5 in AD and controls. The SPINK5 gene polymorphisms were analyzed using the PCR and RFLP methods. Results For the four non‐synonymous SNPs, A1103G(Asn368Ser), G1156A(Asp386Asn), G1258A(Glu420Lys), G2475T(Glu825Asp) in SPINK5, the allelic frequencies in the AD cohort were 0.55 for 1103G, 0.57 for 1156A, 0.54for 1258A, 0.62 for 2475T, consistent with those already published in the original British and Japanese cohorts. The T allele of SNP 2475G > T was found to be significantly associated with AD. There were significant differences in genotype frequencies for G1258A(Glu420Lys) and G2475T(Glu825Asp) but not for A1103G(Asn368Ser) and G1156A(Asp386Asn). Genotypes GA(420Glu/Lys), TT (2475Asp/Asp) and GT(2475Glu/Asp) were significantly more frequent in AD. However, the SPINK5 gene polymorphisms was found not to be associated with AD in regard to either serum IgE levels, concurrent allergic asthma or early onset of AD. Conclusions Our study confirms the association between SPINK5 and AD.     

Polymorphisms within the C3 gene are associated with specific IgE levels to common allergens and super-antigens among atopic dermatitis patients

Abstract:  Atopic dermatitis (AD) is a chronic inflammatory skin disease. Twin and family studies suggest a strong genetic component of the disease. The keratinocytes secrete high amounts of C3 after stimulation with pro-inflammatory cytokines, which may play a functional role in skin inflammation. In this study, we genotyped four different single nucleotide polymorphisms (SNPs) by melting curve analysis using sequence specific hybridization probes in a well-characterized cohort of AD patients. Among four SNPs within C3 gene, higher frequencies of rs10410674 (23.5% vs 12.2%) and rs366510 (13.8% vs 6.5%) were observed in AD patients as compared with control group. None of the tested polymorphisms showed significant association with the risk of the disease phenotype. Analysis of rs10402876 SNP revealed its association with less severe AD disease expression (low SCORAD). Total serum IgE levels were not different among AD patients having any of the four SNPs. However, we observed significantly less serum-specific IgE levels to common allergens ( Dermatophagoides pteronyssinus and birch pollens) and Staphylococcal enterotoxin B in AD patients having rs366510 SNP. Thus, associations of polymorphism within C3 gene with less severe AD disease expression and a weaker sensitization to common allergens suggest the role of these SNPs in the development of AD.     

Beta defensin‐1 gene (DEFB1) polymorphisms are not associated with atopic dermatitis in children and adolescents from northeast Brazil (Recife,Pernambuco)

Background Atopic dermatitis (AD) is a common inflammatory skin disease resulting from the interplay between environmental, immunological and genetic factors. In our study, we investigated the role of three single nucleotide polymorphisms (SNPs) at 5′‐UTR of DEFB1 gene, encoding for the human beta defensin‐1, on the susceptibility to develop AD in a group of Brazilian children and adolescents. Methods Three SNPs, ?20 G/A (rs11362), ?44 C/G (rs1800972), and ?52 G/A (rs1799946) at 5′‐UTR of DEFB1 gene were genotyped in two groups of children and adolescents, one affected by AD (96 subjects), the other healthy (191 individuals), from northeast Brazil. Results ?44 C/G frequencies were comparable between the two groups. The ?20 GG genotype was more frequent in AD subjects than in healthy controls; the ?52 GG, conversely, was more frequent in healthy controls than in AD. However, both these differences did not reach statistical significance. Also, association between SNPs and AD severity has been shown. The analysis of DEFB1 haplotypes did not highlight any association of the three SNPs with AD development or disease severity. Conclusions Our results seem to exclude a role for the ?44 C/G DEFB1 SNPs on the pathogenesis and severity of AD, while for the ?20 C/G and ?52 G/A, even if not statistically significant, we evidenced a slight trend for susceptibility (?20 GG) and protection (?52 GG) for the development of AD. However, as controversial findings have been reported in the literature, the role of DEFB1 in the development of AD and in the severity of the phenotype deserves further investigation.     

Association of SPINK5 gene polymorphisms with atopic dermatitis in the Japanese population

BACKGROUND: Netherton's syndrome (NS) is an autosomal recessive disorder characterized by trichorrhexis invaginata ('bamboo hair'), congenital ichthyosiform erythroderma and an atopic diathesis. NS has recently been shown to be due to a defect in the SPINK5 gene, encoding LEKTI, a 15-domain serine protease inhibitor. SPINK5 maps to chromosome 5q31-q32, and has been suggested to be a locus predisposing to atopy in general. Recently, coding polymorphisms in SPINK5 exons 13 and 14 have been reported to be associated with atopy, asthma and atopic dermatitis (AD). OBJECTIVES: To examine whether these polymorphisms are also associated with AD in Japan. METHODS: We characterized eight polymorphisms in SPINK5 exons 13 and 14 in 124 Japanese patients with AD and 110 healthy controls. The polymorphisms we examined were IVS12-26C-->T, IVS12-10A-->G, 1103A-->G (Asn368Ser, in exon 13), 1156G-->A (Asp386Asn, in exon 13), 1188T-->C (His396His, in exon 13), IVS13-50G-->A, 1258G-->A (Glu420Lys, in exon 14) and IVS14+19G-->A. RESULTS: We found significant associations between seven of these polymorphisms and AD in Japanese patients. CONCLUSIONS: This study confirms the previous suggestion of an association between SPINK5 and AD.     

Lack of association of CCR4 single nucleotide polymorphism with atopic dermatitis in Japanese patients

CCR4, a member of the CC chemokine receptor family, is believed to play an important role in the pathogenesis of atopic dermatitis. To examine whether CCR4 single nucleotide polymorphism (SNP) is associated with susceptibility to atopic dermatitis, we investigated the allele and genotype frequencies of C1014T SNP of CCR4 in 198 Japanese patients with atopic dermatitis and controls by a PCR-restriction fragment length polymorphism method. There was no significant difference in allele or genotype frequencies between patients with atopic dermatitis and controls. Serum IgE levels and peripheral blood eosinophil counts were not significantly different among genotypes. There was also no significant difference in allele or genotype frequencies between the patient subgroup with and without asthma, with mild or moderate disease, with and without family history of atopic dermatitis, or with and without family history of atopic disorders. C1014T SNP of CCR4 does not appear to be associated with susceptibility to atopic dermatitis in Japanese patients.     

Analysis of GM-CSF gene polymorphisms (3606T/C and 3928C/T) in Japanese patients with atopic dermatitis

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is thought to play an important role in the pathogenesis of atopic dermatitis. To examine whether GM-CSF single nucleotide polymorphisms (SNPs) are associated with susceptibility to atopic dermatitis, we investigated the genotype and allele frequencies of the SNPs 3606T/C and 3928C/T of the GM-CSF gene in 181 Japanese patients with atopic dermatitis and 100 controls, using a PCR restriction fragment length polymorphism method. A strong linkage disequilibrium existed between the polymorphisms 3606 and 3928, suggesting two common GM-CSF haplotypes, 3606*T-3928*C and 3606*C-3928*T. However, there was no significant difference in genotype or allele frequencies between patients with atopic dermatitis and controls for either of the two polymorphisms, thus GM-CSF SNPs do not appear to be associated with susceptibility to atopic dermatitis in Japanese patients. A large-scale study is necessary to confirm these findings.     

Are Podoplanin Gene Polymorphisms Associated with Atopic Dermatitis in Koreans?

Background

The histologic characteristics of atopic dermatitis (AD) include perivascular edema and dilated tortuous vessels in the papillary dermis. A single nucleotide polymorphism (SNP) of the fms-related tyrosine kinase 4 (FLT4) gene is associated with AD.

Objective

To investigate the associations between podoplanin (PDPN) gene SNPs and AD.

Methods

We genotyped 9 SNPs from 5 genes of 1,119 subjects (646 AD patients and 473 controls). We determined the promoter activity of 1 SNP (rs355022) by luciferase assay; this SNP was further investigated using 1,133 independent samples (441 AD patients and 692 controls).

Results

The rs355022 and rs425187 SNPs and the C-A haplotype in the PDPN gene were significantly associated with intrinsic AD in the initial experiment. The rs355022 SNP significantly affected promoter activity in the luciferase assay. However, these results were not replicated in the replication study.

Conclusion

Two SNPs and the C-A haplotype in the PDPN gene are significantly associated with intrinsic AD; although, the results were confirmed by luciferase assay, they could not be replicated with independent samples. Nevertheless, further replication experiments should be performed in future studies.     

IL-33和IL1RL1基因单核苷酸多态性与特应性皮炎相关性研究

目的：分析IL-33和IL1RL1基因单核苷酸多态性(SNPs)与特应性皮炎（AD）的相关性。方法：PCR-SSP方法检测89例AD患者和138名正常对照组受试者IL-33和IL1RL1编码基因的等位基因和基因型频率。结果：AD患者的IL-33 rs1800925 C等位基因的频率高于对照组，而T等位基因和rs764706552等位基因G低于对照组（均P＜0.001）。IL-33 rs1800925基因型CC和rs764706552基因型CG与AD显著正相关（均P＜0.001）。两组患者的IL1RL1基因的等位基因和基因型频率无明显差异（均P＞0.05）。结论：IL-33基因可能与AD的发病相关。     

Polymorphisms in human histamine receptor H4 gene are associated with atopic dermatitis

Background Atopic dermatitis (AD) is a chronic skin disease affecting more than 15% of children and 2% of adults. A strong connection between genetic factors and AD has been described for a long time. Histamine receptor H4 (HRH4) has been shown to be related to different kinds of allergic and autoimmune disorders. However, an association between HRH4 and AD has not yet been reported. Objectives To examine a possible association between HRH4 and AD. Methods Genomic DNA from 301 patients with AD and 313 healthy controls was extracted and three exons of HRH4 were sequenced. Results We found three new single nucleotide polymorphisms (SNPs) in HRH4 which were significantly associated with AD: ss142022671 [odds ratio (OR) 1·87, 95% confidence interval (CI) 1·24–2·81; P = 0·002], ss142022677 (OR 4·40, 95% CI 2·42–8·00; P = 1·5 × 10^?7) and ss142022679 (OR 4·26, 95% CI 2·38–7·61; P = 1·3 × 10^?7). The SNPs ss142022677 and ss142022679 were found to be in strong linkage disequilibrium (D’ = 0·98; r² = 0·92). Two‐SNP haplotype analysis (ss142022677 and ss142022679) showed that the major AA haplotype was protective against AD (OR 0·22, 95% CI 0·12–0·40; P = 3·1 × 10^?8) and the minor TT haplotype was significantly associated with AD (OR 4·13, 95% CI 2·27–7·54; P = 6·6 × 10^?7). In addition, in a three‐SNP haplotype analysis (ss142022671, ss142022677 and ss142022679), the major TAA haplotype was protective against AD (OR 0·46, 95% CI 0·31–0·69; P = 0·0001), while the complementary ATT haplotype was found to be significantly associated with AD (OR 3·81, 95% CI 2·03–7·14; P = 8·3 × 10^?6). Conclusions Polymorphisms of ss142022671, ss142022677 and ss142022679 in HRH4 are associated with AD.     

Relationship between Kaposi's varicelliform eruption in Japanese patients with atopic dermatitis treated with tacrolimus ointment and genetic polymorphisms in the IL-18 gene promoter region

Kaposi's varicelliform eruption is the most important problem in treating patients with atopic dermatitis (AD) with tacrolimus ointment. It has been considered that Kaposi's varicelliform eruption occurs due to decreased levels of interleukin (IL)-18. The aim of this study was to examine the relationship between Kaposi's varicelliform eruption and genetic polymorphisms in the IL-18 gene. IL-18 gene promoter polymorphisms were analyzed in 21 AD patients treated with tacrolimus ointment and in 100 healthy volunteers. Six AD patients with Kaposi's varicelliform eruption during the treatment with tacrolimus ointment showed significantly higher frequency in G-to-C mutations at the IL-18 gene promoter region -137 compared with 15 AD patients without Kaposi's varicelliform eruption. The 15 AD patients without Kaposi's varicelliform eruption as well as 100 healthy volunteers did not have mutations of G-to-C at the IL-18 gene promoter region -137. These results suggest that the onset of Kaposi's varicelliform eruption following the treatment with tacrolimus ointment is associated with the mutation of G-to-C in the IL-18 gene promoter region -137, and that caution is required when using tacrolimus ointment for treating AD patients with this mutation.     

中间丝聚合蛋白基因多态性与特应性皮炎发病及临床表型的相关性

目的 探讨中间丝聚合蛋白(FLG)基因多态性与特应性皮炎(AD)发病及临床表型的相关性.方法 采用问卷调查的形式收集261例AD患者伴发过敏性鼻炎、哮喘病史和疾病严重度评分等资料,对部分患者进行混合食物过敏原和混合吸人性过敏原筛选、血清总IgE抗体和嗜酸性粒细胞阳离子蛋白水平检测.采用重叠PCR和DNA测序法对上述AD患者和276例健康对照FLG基因3号外显子17个多态性位点(R444G、T454A、P478S、H519N、D836D、S1482Y、A1805V、R1891Q、1961Q、S2166S、Y2194H、H2330H、D2339N、S2366T、E2398Q、K2444E、E2652D)进行基因分型.结果 二项逻辑回归分析和卡方检验未发现17种FLG多态位点与AD发病相关(均P＞0.05).H519N与AD伴发哮喘相关(x2=8.680,P=0.011),AA基因型可增加AD患者发生哮喘的风险(P=0.004,OR=1.061,95％ CI 1.016 ～ 1.109).S2366T和K2444E与AD患者食物敏感相关(x2值分别为6.520和6.121,P值分别为0.038和0.047),S2366T的GG+ GC基因型(P=0.012,OR=1.396,95％CI 1.054～1.849)和G等位基因(P=0.037,OR=1.350,95％CI 1.008～ 1.807)可提高AD患者食物敏感的风险.K2444E的AA+ AG基因型(P=0.013,OR=1.393,95％ CI 1.049 ～ 1.850)和G等位基因(P=0.028,OR=1.380,95％ CI 1.025 ～ 1.857)可提高AD患者食物敏感的风险.结论 中国汉族人群FLG基因多态性可能是一些AD相关临床表型的危险因素,H519N可能与AD伴发哮喘相关,S2366T和K2444E则可能与AD伴食物敏感相关.     

Specific filaggrin mutations cause ichthyosis vulgaris and are significantly associated with atopic dermatitis in Japan

Mutations in the gene encoding filaggrin (FLG) have been identified as the cause of ichthyosis vulgaris (IV) and shown to be major predisposing factors for atopic dermatitis (AD). However, these studies have been mainly carried out in European populations. In early 2007, we identified two Oriental-specific FLG mutations in four Japanese families with IV and reported that filaggrin mutations were also significant predisposing factors for AD in Japan. However, the frequency of FLG mutations observed in our Japanese AD cohort (5.6%), was much lower than that seen in Europeans (up to 48%). Here, we studied a further seven Japanese families with IV and identified two additional nonsense mutations in FLG, S2889X, and S3296X. We found that more than 20% of patients in our Japanese AD case series carry FLG mutations, and there is significant statistical association between the four mutations and AD (chi(2) P=8.4 x 10(-6); heterozygote odds ratio 7.57, 95% CI 2.84-23.03). These data emphasize that skin-barrier impairment due to reduced filaggrin expression plays an important role in the pathogenesis of AD and sheds further light on the genetic architecture of atopy in Japan.     

Genetic polymorphisms of the HCR gene and a genomic segment in close proximity to HLA-C are associated with patients with psoriasis in Taiwan

BACKGROUND: Although psoriasis vulgaris (PV) is strongly associated with HLA-Cw*0602, it has been proposed that the association of Cw*0602 is due to linkage disequilibrium and that other nearby genes are involved in PV susceptibility. The alpha-helix coiled-coil rod homologue (HCR) gene, located 110 kb telomeric to the HLA-C locus, is presumed to be one of the PV candidate genes. Recently, a 10-kb genomic segment, centromeric to HLA-C, defined by two new single nucleotide polymorphisms (SNPs) n.7*A and n.9*C, was found to have a stronger association with psoriasis than the HCR gene. Until now, no study of the association of the HCR gene, SNPs n.7, and n.9 has been conducted on Chinese patients with psoriasis. OBJECTIVES: We aimed to determine whether the genetic polymorphisms of the HCR gene, SNPs n.7*A, and n.9*C were associated with an increased risk of psoriasis in Chinese patients. METHODS: Using direct sequencing of the HCR gene and the genomic region containing SNPs n.7 and n.9, we investigated the HCR gene, SNPs n.7, and n.9 for disease association in 115 Chinese patients with psoriasis and 103 control subjects. The HCR SNPs were confirmed by denaturing high performance liquid chromatography. Genotyping for HLA-Cw*0602 was also carried out using sequence-based typing. RESULTS: We observed a different allelic distribution between patient and control groups at nucleotide positions 386, 404, 1802 and 2406 of the HCR gene, and SNPs n.7, and n.9. The associations were much stronger in early onset PV patients (for HCR-386*T and HCR-404*T, odds ratio = 5.63, Pc < 0.0001). The HLA-Cw*0602 also displayed a similar association with PV (odds ratio = 5.4, Pc < 0.0001). Moreover, SNP n.7*A, SNP n.9*C, Cw*0602, HCR-386*T, HCR-404*T and HCR-1802*T were in linkage disequilibrium with each other. Haplotype-based association analysis showed SNP n.7*A-SNP n.9*C-Cw*0602-HCR-386*T-HCR-404*T-HCR-1802*T-HCR-2406*G as a major susceptibility haplotype in this Chinese population (for early onset patients, odds ratio = 5.15, Pc < 0.0001). CONCLUSIONS: Our results indicate that the HCR gene, SNP n.7*A, and SNP n.9*C as well as Cw*0602 are major susceptibility markers for psoriasis in Chinese patients.