Tau-tubulin kinase-1 gene variants are associated with Alzheimer's disease in Han Chinese

Tau-tubuline kinase 1 (TTBK1) is a recently discovered brain-specific protein kinase involved in tau phosphorylation at AD-related sites. A recent large study has identified significant association of two single nucleotide polymorphisms (SNPs) (rs2651206 and rs7764257) in the TTBK1 gene with late-onset Alzheimer's disease (LOAD) in Spanish. Here, we performed a case–control study to clarify whether the risk for LOAD might be influenced by these polymorphisms in a large Chinese cohort consisting of 400 patients and 388 healthy controls. The minor alleles of the rs2651206 polymorphism within TTBK1 was significantly associated with a reduced risk of LOAD (odds ratio/OR = 0.69, P = 0.011). Furthermore, rs2651206 polymorphism was still strongly associated with LOAD (OR = 0.72, P = 0.05) after adjusted for age, gender, and the apolipoprotein E (APOE) ?4 status. Haplotype analysis identified the TG haplotype, deriving from the two minor alleles, to decrease the risk of LOAD (OR = 0.78, P = 0.037). This study provides the evidence that variations in the TTBK1 gene may play an important role in the pathogenesis of sporadic LOAD in a Han Chinese population.     

Supportive evidence for neuregulin 1 as a susceptibility gene for schizophrenia in a Japanese population

Schizophrenia is a complex genetic disorder and affects approximately 1% of the population worldwide. Recently, Stefansson et al. identified neuregulin 1 (NRG1) on 8p12 as a susceptibility gene for schizophrenia in the Icelandic population. It was reported that the at-risk haplotype (“Hapice”) constructed from five SNPs and two microsatellite markers was found to be over-represented in patients with schizophrenia compared to controls. Since then several independent studies have supported the association of NRG1 with schizophrenia. We performed a case–control association study using the four SNPs in a Japanese sample. We genotyped three SNPs (SNP8NRG221533, SNP8NRG241930, and SNP8NRG243177) from Stefansson et al. and one SNP (rs1081062) located in intron 1 of NRG1. There were no significant differences in allele frequencies for each SNP between cases and controls, however, homozygotes of minor alleles in SNP8NRG241930, SNP8NRG243177, and rs1081062 were associated with an increased risk of schizophrenia (P = 0.025, OR = 4.14; P = 0.041, OR = 1.43; and P = 0.0023, OR = 3.06, respectively). Furthermore, the haplotype constructed from four SNPs shows a significant association with schizophrenia (permutation P = 0.026). Our data support the hypothesis that NRG1 gene is a susceptibility gene for schizophrenia.     

SNP/haplotype associations of CCR2 and CCR5 genes with severity of chagasic cardiomyopathy

Background

Chronic inflammation plays a major role in the tissue injury seen in the chronic chagasic cardiomyopathy. The CCR2 and CCR5 chemokine receptors are involved with the type of cellular infiltrate present in cardiac tissue and CCR5-gene variants were previously associated with this pathology.

Methods and results

This is a replication study in an independent cohort with larger sample size. Nine SNPs of CCR5 and CCR2 were typified to confirm the association previously found with Chagas disease. Evidence of association with severity was found for the A allele of rs1799864 of CCR2 (p_ad = 0.02; OR = 1.91, 95% CI = 1.10–3.30), the T allele of the rs1800024 of CCR5 (p_ad = 0.01; OR = 1.95, 95% CI = 1.13–3.38), and the HHF^∗2 haplotype (p = 0.03, OR = 1.65, 95% CI = 1.03–2.65). These results were replicated in the study combined with previous data. In this analysis it was replicated the allele T of rs2734648 (p_ad = 0.009, OR = 0.52, 95% CI = 0.32–0.85) with protection. In addition, the allele G of rs1800023 (p_ad = 0.043, OR = 0.61, 95% CI = 0.38–0.98), and the HHC haplotype (p = 0.004, OR = 0.62, 95% CI = 0.44–0.86) were also associated with protection. In contrast, the allele A of rs1799864 of CCR2 (p_ad = 0.009; OR = 1.90, 95% CI = 1.17–3.08); and the allele T of rs1800024 of CCR5 (p_ad = 0.005, OR = 1.98, 95% CI = 1.22–3.23) were associated with greater severity. No evidence of association between symptomatic and asymptomatic patients was observed.

Conclusions

These results confirm that variants of CCR5 and CCR2 genes and their haplotypes are associated with the severity but not with susceptibility to develop chagasic cardiomyopathy.     

NEDD9 rs760678 polymorphism and the risk of Alzheimer's disease: A meta-analysis

The NEDD9 rs760678 polymorphism has been extensively investigated for association to Alzheimer's disease (AD), however, results of different studies have been inconsistent. The objective of this study is to assess the relationship of NEDD9 rs760678 polymorphism and AD risk by using meta-analysis. Systematic searches of electronic databases Pubmed and Embase, as well as hand searching of the references of identified articles were performed. Statistical analyses were performed using software Revman 4.2 and STATA 11.0. A total of 4436 cases and 4420 controls in 11 case–control studies were included. The results indicated that the homozygote GG had a 13% decreased risk of AD, when compared with the C allele carriers (CC + CG) (OR = 0.87, 95%CI = 0.77–0.99, P = 0.04 for GG vs. CG + CC). In the subgroup analysis by ethnicity, significant decreased risk was associated with homozygote GG or G allele carriers in Caucasians (OR = 0.84, 95%CI = 0.74–0.96, P = 0.008 for GG vs. CG + CC; OR = 0.79, 95%CI = 0.69–0.91, P = 0.001 for GG vs. CC; OR = 0.90, 95%CI = 0.84–0.96, P = 0.002 for G vs. C), but not in Asians. This meta-analysis suggests that the GG genotype of NEDD9 rs760678 polymorphism would be a protective factor for AD in Caucasians but not in Asians. To further evaluate the effect of gene–gene and gene–environmental interactions between NEDD9 rs760678 polymorphism and the risk of AD, more studies with larger number of subjects are required.     

Study of thyroid hormone receptor alpha gene polymorphisms on Alzheimer's disease

Because the action of thyroid hormone (T3) is involved in adult cognitive functions, we wanted to assess the association between THRA gene polymorphisms, which encodes the T3 nuclear receptor TRα1, and Alzheimer's disease (AD) risk.We analysed 5 single nucleotide polymorphisms (SNPs) of THRA, covering the known common genetic variability of the gene, in the Lille AD case-control study (710 cases/597 controls). We observed that subjects bearing the rs939348 TT genotype had a tendency to have a higher risk of developing AD (adjusted OR [95%CI] = 1.71 [0.99-2.95] p = 0.06). We extended our finding to three other independent AD case-control studies and observed similar trends. When combining the 4 studies (1749 cases/1339 controls), we observed an overall significant higher risk of AD in TT subjects (adjusted OR [95%CI] = 1.42 [1.03-1.96], p = 0.03) compared with C allele bearers. However, when combining our data with the available data coming from 2 American genome wide association studies on AD, we observed a weak and not significant association (OR = 1.19 [0.97-1.45], p = 0.10).The relationship between the genetic variability of the THRA gene and AD risk remains uncertain but cannot be entirely excluded.     

Ubc9 gene polymorphisms and late-onset Alzheimer's disease in the Korean population: A genetic association study

Ubiquitin-conjugating enzyme E2I (Ubc9) ligates small ubiquitin-related modifier (SUMO) to target proteins, resulting in changes of their localization, activity, or stability. Sumoylation of amyloid precursor protein (APP) was reported to be associated with decreased levels of beta amyloid (Aβ) aggregates, suggesting that sumoylation may play a role in the pathogenesis of Alzheimer's disease (AD). We investigated the association between genetic variations of Ubc9 gene (UBE2I) and late-onset Alzheimer's disease (AD). Five single nucleotide polymorphisms (SNPs) in UBE2I were genotyped in the DNA samples of 312 AD patients, 347 subjects with mild cognitive impairment (MCI), and 489 cognitively healthy controls. The genotype distribution of a polymorphism in intron 7 (rs761059) differed between AD cases and controls, with an adjusted odds ratio (OR) of 1.45 (p = 0.046, 95% CI: 1.01–2.08). One haplotype (ht2 CAGAG) was found in 14.0% of the AD patients and in 11.1% of the controls (p = 0.04, OR = 1.43. 95% CI; 1.01–2.01). Stratification by the ApoE-?4 allele gave no significant difference between the groups. When the samples were stratified by gender, the genotypes of two SNPs (rs8052688, rs8063) were significantly associated with the risk of MCI among women. Our investigation suggests that UBE2I polymorphisms might be associated with a risk of AD and MCI.     

Association between two single nucleotide polymorphisms of PDCD6 gene and increased endometriosis risk

Programmed cell death 6 (PDCD6), a calcium binding protein of the penta EF-hand protein family, and its receptors are involved in regulation of apoptosis pathways. To evaluate the relationship between genetic polymorphisms of PDCD6 gene and endometriosis (ED) risk, we investigated the association of two single nucleotide polymorphisms (SNPs) of PDCD6 gene (rs4957014 and rs3756712) in 220 endometriosis patients and 386 unrelated healthy controls. The genotypes of these two SNPs were determined by using polymerase chain reaction (PCR)–restriction fragment length polymorphism (RFLP) and DNA sequencing methods. Significantly increased endometriosis risk was observed to be associated with G allele of rs4957014 locus (OR = 1.31, 95% CI = 1.03–1.69). We have also observed increased ED risk was statistically associated with rs4957014 polymorphism in a dominant model (OR = 1.52, 95% CI = 1.09–2.13). Although no association has been found between ED risk and the allele frequencies of rs3756712 locus (a marginal P = 0.066, OR = 1.27, 95% CI = 0.98–1.65), but in a dominant model, increased endometriosis risk was significantly associated with rs3756712 polymorphism (OR = 1.54, 95% CI = 1.11–2.17). In conclusion, the current study indicates that PDCD6 gene may be a new susceptibility gene to endometriosis.     

Association between somatostatin gene polymorphisms and sporadic Alzheimer's disease in Chinese population

Recent evidence has suggested that down-regulation of somatostatin (SST) expression in the human brain during early stages of aging leads to an elevation in the steady-state levels of Aβ and therefore may be involved in Alzheimer's disease (AD) progression. We hypothesized that alterations in the SST gene might alter its expression or function and also play a role in the pathogenesis of sporadic AD (SAD). First, we sequenced the entire SST gene in 25 randomly selected controls and 25 SAD patients and then screened for C/T polymorphisms (rs4988514) in the 3′ un-translated region. We genotyped rs4988514 polymorphisms as well as apolipoprotein ?4 (APOE ?4) status in 309 SAD patients and 276 normal controls with restriction fragment length polymorphism (RFLP) analysis. Results showed that the C allele of the rs4988514 polymorphism had an increased incidence in the SAD group compared to the control group (p = 0.042). In subjects with the APOE ?4 allele, the presence of both the CC genotype and the C allele of this polymorphism were elevated in the SAD group compared to the control group (genotype p = 0.027, allele p = 0.011). In the whole study group, the age, sex, and APOE ?4 adjusted OR for the risk of AD in C allele carriers was 1.313 (95%CI = 1.068–2.234, p = 0.027) whereas within only APOE ?4 allele carriers, the adjusted OR increased to 2.734 (95%CI = 1.236–5.862, p = 0.012). Our results supported the notion that the C allele of the rs4988514 polymorphism may increase the risk for AD in the Chinese population and possibly have additive effect with the APOE ?4 allele.     

Association between promoter polymorphisms of the nicastrin gene and sporadic Alzheimer's disease in North Chinese Han population

Increasing evidences have shown that nicastrin (NCSTN) plays a crucial role in γ-cleavage of the amyloid precursor protein (APP). Inhibition of NCSTN demonstrated an altered γ-cleavage activity, suggesting its potential implication in developing Alzheimer's disease (AD). We detected the NCSTN gene promoter region in 359 sporadic AD (SAD) patients and 331 controls and found three promoter single nucleotide polymorphisms (SNPs): −1216C/A (rs2147471), −796T/G (rs10752637) and −436C/T (rs1324738). For −1216C/A, there were significant differences in the allele and genotype frequency between AD and control subjects (allele P = 0.031, genotype P = 0.017). The allele and genotype frequencies remained significant before and after APOE?4 stratification. The −1216CC carriers increased 2-fold risk for the development of SAD compared to the carriers with −1216CA and AA genotypes (OR = 2.049, 95%CI = 1.410–2.976, P = 0.000). For −796T/G, there were significant differences in the genotype frequency between SAD and control subjects (P = 0.009). This trend is still obvious in the subjects without APOE?4 allele. The −796GG carriers might decrease the risk compared to the carriers with −796TG and TT genotypes (OR = 0.602, 95%CI = 0.393–0.932, P = 0.022). No significant difference was detected either in genotype or in allele frequencies between SAD and control for −436C/T, even after APOE?4 stratification. The haplotype −1216A/−796G may be a protective factor for SAD (OR = 0.795, 95%CI = 0.636–0.995, P = 0.045). Our investigation suggests that −1216C/A and −796T/G are probably related to the development of SAD.     

Gender differences in the IL6 -174G>C and ESR2 1730G>A polymorphisms and the risk of Parkinson's disease

The −174G>C (rs1800795) single nucleotide polymorphism (SNP) in the promoter of the interleukin-6 (IL6) gene and the 1730G>A (rs4986938) SNP in the estrogen receptor beta (ESR2) may influence the risk of Parkinson's disease (PD). We investigated these SNPs in 380 unrelated US Caucasian PD cases and 522 controls, including 452 individuals of Ashkenazi Jewish (AJ) origin (260 PD, 192 controls). The G allele of the −174G>C SNP was more common in AJ PD cases (p = 0.033) as well as in Non-Jewish (NJ) men with PD (p = 0.022). The GG genotype increased the risk of PD by over two fold in NJ men (OR = 2.11, 95%CI: 1.14-3.89, p = 0.017), and approached significance in the total AJ group with PD (OR = 1.42, 95%CI: 0.97-2.06, p = 0.067). The A allele of the ESR2 1730G>A SNP was associated with a decreased risk for PD in AJ women, and in this group, having the AA genotype decreased the risk of PD by half (OR = 0.45, 95%CI: 0.22-0.92, p = 0.029). Our data supports a role for the IL6 −174G>C G allele in AJ individuals overall. In NJ Caucasians, this role appears to be gender mediated. In both groups, the effect is independent from ESR2 1730G>A. A separate association for the ESR2 1730G>A SNP was found exclusively in women of AJ descent. Other polymorphisms in tight linkage disequilibrium with the SNP differentially influencing expression, ethnic differences in allele distribution, and gender differences in genetic load related to PD, may underlie our findings. Larger studies in diverse populations, including analysis of surrounding regions are recommended.     

A search for age-related macular degeneration risk variants in Alzheimer disease genes and pathways

Several lines of inquiry point to overlapping molecular mechanisms between late-onset Alzheimer disease (AD) and age-related macular degeneration (AMD). We evaluated summarized results from large genome-wide association studies for AD and AMD to test the hypothesis that AD susceptibility loci are also associated with AMD. We observed association of both disorders with genes in a region of chromosome 7, including PILRA and ZCWPW1 (peak AMD SNP rs7792525, minor allele frequency [MAF] = 19%, odds ratio [OR] = 1.14, p = 2.34 × 10⁻⁶), and with ABCA7 (peak AMD SNP rs3752228, MAF = 0.054, OR = 1.22, p = 0.00012). Next, we evaluated association of AMD with genes in AD-related pathways identified by canonical pathway analysis of AD-associated genes. Significant associations were observed with multiple previously identified AMD risk loci and 2 novel genes: HGS (peak SNP rs8070488, MAF = 0.23, OR = 0.91, p = 7.52 × 10⁻⁵), which plays a role in the clathrin-mediated endocytosis signaling pathway, and TNF (peak SNP rs2071590, MAF = 0.34, OR = 0.89, p = 1.17 × 10⁻⁵), which is a member of the atherosclerosis signaling and the LXR/RXR activation pathways. Our results suggest that AMD and AD share genetic mechanisms.     

Association study between two novel single nucleotide polymorphisms and sporadic Parkinson's disease in Chinese Han population

Two novel single nucleotide polymorphisms (SNPs) (rs6812193 and rs11868035) were recently identified to be associated with Parkinson's disease (PD) in a Web Based Genome-Wide Association Study. Herein, we conducted a case–control study to evaluate the possible associations between these two SNPs and PD in Chinese Han population. All subjects (501 sporadic PD patients and 502 normal controls) were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis with these two SNPs. Chi-square test revealed no significant difference in either genotype frequencies or allele frequencies, even after being stratified by age. But we found that the genotype and allele frequency of rs6812193 shows difference between male patients and male controls (p = 0.031, OR = 0.584; p = 0.037, OR = 0.606) but none in the female. Our findings suggest that rs11868035 may have no association with PD in Chinese population and rs6812193 may have marginal association with PD in male Chinese population. However, due to the limited data in the present study, replication studies in larger sample and other populations are required.     

IL21 and IL21R polymorphisms and their interactive effects on serum IL-21 and IgE levels in patients with chronic hepatitis B virus infection

Interleukin (IL)-21 may affect both T-cell and B-cell responses and was suggested to be involved in response to HBV infection. This study explored IL21rs907715 and rs2221903 and IL21R T-83C and rs3093301 polymorphisms and serum IL-21 and IgE levels in 395 patients with chronic HBV infection, 75 HBV infection resolvers and 174 healthy controls. IL21R T-83C was not polymorphic in the study populations. IL21 rs2221903 AG was less frequent in HBV patients than in resolvers (p < 0.001, OR = 0.364, 95% CI = 0.211–0.629) or in controls (p = 0.017, OR = 0.589, 95% CI = 0.381–0.911). IL21R rs3093301 TT was more frequent in HBV patients than in controls [p value after Bonferroni correction (p_c) = 0.022, OR = 1.908, 95% CI = 1.158–3.142] and more frequent in resolvers than in controls (p_c = 0.010, OR = 2.965, 95% CI 1.375–6.392). The carriage of IL21 rs2221903 AG/IL21R rs3093301 CT + IL21 rs2221903 AG/IL21R rs3093301 TT was less frequent in patients than in resolvers (p_c = 0.007, OR = 0.236, 95% CI = 0.096–0.579) and more frequent in resolvers than in controls (p_c = 0.014, OR = 4.354, 95% CI = 1.660–11.420). IL21 rs2221903 was, by interaction with IL21R rs3093301, associated with serum IL-21 and IgE levels in HBV patients. It is suggested that IL21 rs2221903 and IL21R rs3093301 polymorphisms may, independently or interactively, affect the susceptibility to and/or persistence of HBV infection potentially through altering IL-21 and IgE production.     

HLA rs3129882 variant in Chinese Han patients with late-onset sporadic Parkinson disease

Recently, the rs3129882 variant in intron 1 of HLA-DRA was found to be associated with late-onset sporadic Parkinson disease (PD) in Americans of European ancestry. To evaluate whether the same variant is related to PD in Chinese population, we investigated late-onset sporadic PD patients of Chinese Han ethanicity in Mainland China. We found significant difference in genotypic and allele distribution between patients and control subjects (χ² = 6.446, p = 0.040 for genotypic distribution; χ² = 5.762, p = 0.016 for allele distribution), suggesting this variant is associated with late-onset sporadic PD in Chinese Han population.     

Insulin-like growth factor 1 (IGF1) polymorphism is associated with Alzheimer's disease in Han Chinese

A review of pathogenic findings in Alzheimer's brains and the functional consequences of altered insulin-like growth factor 1 (IGF1) input to the brain suggest the association between Alzheimer's disease (AD) and the disrupted IGF1 signaling. Recently, the identification of polymorphism rs972936 that was associated with both an increased risk of AD and high circulating levels of IGF1 was reported in Southern European population. In order to evaluate the involvement of the IGF1 polymorphism in the risk of developing late-onset Alzheimer's disease (LOAD) in Chinese, we performed an independent case-control association study in a Han Chinese population (794 LOAD cases and 796 controls). There were significant differences in genotype and allele frequencies between LOAD cases and controls (genotype P = 0.006, allele P = 0.047). The T allele of rs972936 demonstrated a 1.16-fold risk for developing LOAD when compared with the C allele, which diverges to the report in the Caucasian population. After stratification by apolipoprotein E (APOE) ?4-carrying status, rs972936 polymorphism was only significantly associated with LOAD in non-ApoE ?4 allele carriers (genotype P = 0.002, allele P = 0.039). Multivariate logistic regression analysis also conferred this positive association between the SNP rs972936 and LOAD in the recessive and additive model after adjustment for age, gender, and the ApoE ?4 carrier status. These results suggest that IGF1 polymorphism has a possible role in changing the genetic susceptibility to LOAD in a Han Chinese population.     

Polymorphisms in thymic stromal lymphopoietin gene demonstrate a gender and nasal polyposis-dependent association with chronic rhinosinusitis

Background

Recent studies have suggested that thymic stromal lymphopoietin (TSLP), a key cytokine involved in the dendritic cell-mediated activation of Th2-mediated inflammatory responses, is significantly increased in nasal polyps from atopic individuals. Our objective was therefore to explore firstly any associations between single nucleotide polymorphisms (SNPs) in and around the TSLP gene and development of chronic rhinosinusitis (CRS; with (CRSwNP) or without (CRSsNP) nasal polyps and, and secondly the influence of nasal polyposis and gender.

Methods

A population-based case-control association analysis was performed in a Han Chinese cohort. DNA extracted from peripheral blood leukocytes from 638 subjects with CRS (306 CRSwNP and 332 CRSsNP) and 325 healthy controls was assessed for 11 SNPs in and around TSLP gene, selected from the Chinese HapMap genotyping dataset. Genetic association tests were performed using the Haploview and STATA software package.

Results

Single-locus analysis of CRS risk, showed no significant differences in allele or genotype frequencies between CRS subjects and controls. Stratified analyses of association between the selected SNPs and CRS adjusted for gender demonstrated that rs13156068 (CC genotype: P = 0.010, OR = 0.289) and rs764917 (CC genotype: P = 0.040, OR = 0.509) were significantly protective against CRS, whereas rs6886755 (GT genotype: P = 0.040, OR = 0.509) presented a risk among females. In contrast, rs764917 (CA genotype: P = 0.033, OR = 1.553) presented risk for CRS in males. Furthermore, SNPs rs252706 (AA genotype: P = 0.012, OR = 0.552) and rs764917 (CA genotype: P = 0.001, OR = 0.182) displayed protective roles among CRSwNP, but not CRSsNP, subjects.

Conclusions

This study suggests that SNPs in TSLP gene may exert a gender and/or nasal polyposis-dependent risk for development of CRS in Chinese subjects.     

A meta-analysis about the association between −1082G/A and −819C/T polymorphisms of IL-10 gene and risk of type 2 diabetes

The present meta-analysis was conducted to investigate the association between the −1082G/A and −819C/T polymorphisms of the IL-10 gene and risk of type 2 diabetes mellitus (T2DM). Relevant articles were identified by searching PubMed, Embase, and Web of Science. Pooled odds ratios (ORs) were used to assess the strength of the association between target polymorphisms and the risk of T2DM. Significant associations between the −1082G/A polymorphism and T2DM were found for the allele contrast (OR = 0.90, 95% CI: [0.83, 0.98], P = 0.02), homozygote contrast (OR = 0.82, 95% CI: [0.69, 0.97], P = 0.02), and recessive genetic model (OR = 0.85, 95% CI: [0.74, 0.96], P = 0.01). However, no significant association was found for the dominant genetic model (OR = 0.91, 95% CI: [0.80, 1.05], P = 0.08). The association between −819C/T polymorphism and T2DM was significant for the allele contrast (OR = 0.73, 95% CI: [0.64, 0.84], P < 0.01); however, no significant associations were found for −819C/T in the homozygote contrast (OR = 1.01, 95% CI: [0.38, 2.67], P = 0.99), dominant genetic model (OR = 0.94, 95% CI: [0.50, 1.77], P = 0.86), and recessive genetic model (OR = 0.92, 95% CI: [0.50, 1.68], P = 0.78). No significant publication bias was detected. This meta-analysis suggests that allele A of −1082G/A and allele C of −819C/T in the IL-10 gene have potentially protective effects in terms of risk of T2DM.     

The interleukin-6 gene −572C/G promoter polymorphism modifies Alzheimer's risk in APOE ɛ4 carriers

Inflammatory response is involved in the etiopathology of Alzheimer's disease (AD). Interleukin-6 (IL-6), a pleiotropic inflammatory cytokine, was reported to be associated with both increased Aβ aggregation and the appearance of hyperphosphorylated tau in AD brain. To explore the association of genetic variants in the promoter of IL-6 gene with sporadic AD (SAD), a case–control study was conducted in a North Chinese Han population. A systematic screening of IL-6 promoter was performed using direct sequencing and two polymorphisms were obtained including −572C/G (rs1800796) and −384A/T (rs7802308). Definitive genotyping of these markers and apolipoprotein E (APOE) polymorphism were surveyed in 341 SAD patients and 421 controls. The results revealed no significant differences in the distributions of alleles or genotypes between SAD and control groups. However, there was an interaction between −572C/G and APOE genotypes (P = 0.016) using logistic analysis. In the subjects with APOE ?4, there were significant differences in the allele (P = 0.004) and genotype (P = 0.004) distributions of −572C/G polymorphism between SAD and control groups. The −572CC genotype increased risk for AD by 3.301-fold (Wald = 11.093, adjust OR = 3.301, 95% CI = 1.635–6.665, P = 0.001) compared to CG + GG genotype. The present results suggest the −572 polymorphism could modify the risk for SAD in APOE ?4 carriers.     

SPINK5 is associated with early‐onset and CHI3L1 with late‐onset atopic dermatitis

We have recently showed that filaggrin (FLG) mutations are associated only with early‐onset of AD, but not with late‐onset of AD. Consequently, other susceptibility genes should receive attention, especially in patients with late‐onset of AD. Our aim was to assess the associations between development of AD and the polymorphisms rs2303067 in SPINK5 and rs490928 in CHI3L1. A study population of 241 AD patients and 164 healthy controls was genotyped for two polymorphisms (rs2303067 in SPINK5 and rs490928 in CHI3L1). Rs2303067 in SPINK5 was significantly associated with early‐onset AD (≤8 years: p = .003; OR = 2.57) and was characterized by the need for hospitalization (p = .006; OR = 2.76), prolonged duration (≥10 years; p = .008; OR = 2.32) and more body parts affected (p = .015; OR = 2.01). In contrast, rs490928 in CHI3L1 was associated with late‐onset AD (>8 years: p = .048; OR = 1.65) and was characterized by no need for hospitalization (p = .049; OR = 1.59), shorter duration (<10 years; p = .017; OR = 1.94) and fewer body parts affected (p = .049; OR = 1.75). Our results confirmed that different AD phenotypes, specifically early‐ and late‐onset AD, have different genetic backgrounds. Early‐onset AD was associated with rs2303067 in SPINK5, which is involved in skin barrier functioning, and late‐onset was associated with rs4950928 in CHI3L1, which is involved in the immune response. Future studies should examine the early‐ versus late‐onset subgrouping more closely.