Association of 77 polymorphisms in 52 candidate genes with blood pressure progression and incident hypertension: the Women's Genome Health Study.

OBJECTIVE: Genetic risk factors for essential hypertension are largely unknown. The aim of the present study was to assess the association of 77 previously characterized gene variants in 52 candidate genes from various biological pathways with blood pressure (BP) progression and incident hypertension. METHODS: We analyzed data from 18 738 white women who participated in a prospective cohort study and were free of hypertension at baseline. BP progression at 48 months and incident hypertension during the entire follow-up according to the different genotypes were assessed by logistic regression and Cox proportional-hazards models, respectively. RESULTS: At 48 months of follow-up, 7889 of 16 635 women (47.4%) had BP progression. Only three of 70 polymorphisms with a minor allele frequency of at least 2% had a significant association with BP progression. The odds ratio [95% confidence interval (CI)] for 5,10-methylenetetrahydrofolate reductase (MTHFR) rs1801133 (minor allele T), natriuretic peptide precursor A (NPPA) rs5063 (minor allele A) and NPPA rs5065 (minor allele C) were 1.05 (1.00-1.10), 0.84 (0.76-0.94) and 0.93 (0.88-1.00), respectively. After adjustment for multiple testing using the false discovery rate, only the NPPA rs5063 association remained significant. During a median follow-up of 9.8 years, 5540 of 18 738 women developed incident hypertension. Only five of 70 polymorphisms were significantly associated with incident hypertension. The hazard ratio (95% CI) for interleukin 6 (IL-6) rs1800795 (minor allele C), MTHFR rs1801133, NPPA rs5063, nitric oxide synthase 3 rs1799983 (minor allele T) and transforming growth factor, beta 1 rs1800469 (minor allele T) were 0.96 (0.92-1.00), 1.06 (1.02-1.10), 0.88 (0.80-0.96), 1.05 (1.01-1.09) and 1.05 (1.01-1.10), respectively. After adjustment for multiple testing, none of these associations remained significant. CONCLUSION: NPPA gene polymorphisms may have a role in BP progression and incident hypertension. Our data also provide moderate confirmatory evidence of association between MTHFR rs1801133 and the development of hypertension.

Variation in the lymphotoxin-alpha/tumor necrosis factor locus modifies risk of erythema nodosum in sarcoidosis.

Sarcoidosis is a multi-system inflammatory disease with organ involvement that varies by race and sex. Family studies indicate that genes play a role in the etiology and extent of organ involvement in sarcoidosis. In this study, we evaluated whether 25 variants distributed in 19 genes with a known role in inflammation were associated with erythema nodosum status in 659 sarcoidosis patients and 658 controls from A Case-Control Etiologic Study of Sarcoidosis (ACCESS). We found no association with affectation status; however, a variant in the promoter of tumor necrosis factor (TNF) at position -308 was found to be associated with erythema nodosum in Caucasian sarcoidosis patients (study-wide P=0.027). When separated by sex, a variant in intron 1 of lymphotoxin-alpha (LTA), a gene adjacent to TNF, was associated with erythema nodosum in female Caucasian sarcoidosis patients (study-wide P=0.027). These DNA variants frequently occur together in Caucasians, and each variant has individually been associated with erythema nodosum in sarcoidosis patients. These results confirm that variation in the LTA/TNF gene cluster modifies a major skin manifestation of sarcoidosis and may explain the higher rate of erythema nodosum in females with sarcoidosis.

Variants of chemokine receptor 2 and interleukin 4 receptor, but not interleukin 10 or Fas ligand, increase risk of cervical cancer.

Cervical cancer is caused by persistent infection of oncogenic human papillomavirus (HPV). Most infected women clear the virus without developing cervical lesions and it is likely that immunological host factors affect susceptibility to cervical cancer. The impact of the human leukocyte antigen (HLA) locus on the risk of cervical cancer is established and several other genes involved in immunological pathways have been suggested as biologically plausible candidates. The aim of this study was to examine the potential role of polymorphisms in 4 candidate genes by analysis of 1,306 familial cervical cancer cases and 288 controls. The following genes and polymorphisms were studied: Chemokine receptor 2 (CCR-2) V64I; Interleukin 4 receptor alpha (IL-4R) I75V, S503P and Q576R; Interleukin 10 (IL-10) -592; and Fas ligand (FasL) -844. The CCR-2 64I variant was associated with decreased risk of cervical cancer; homozygote carriers of the 64I variant had an odds ratio of 0.31 (0.12-0.77). This association was detected in both carriers and noncarriers of the HLA DQB1*0602 cervical cancer risk allele. The IL-4R 75V variant was associated with increased risk of cervical tumors, cases homozygote for 75V had an odds ratio of 1.91 (1.27-2.86) with a tendency that the association was stronger in noncarriers of the DQB1*0602 allele. We did not find any association for IL-10 -592, or FasL -844, previously reported to be associated with cervical cancer in the Dutch and Chinese populations, respectively.

Parental smoking modifies the relation between genetic variation in tumor necrosis factor-alpha (TNF) and childhood asthma.

BACKGROUND: Polymorphisms in the proinflammatory cytokine genes tumor necrosis factor-alpha (TNF) and lymphotoxin-alpha (LTA, also called TNF-beta) have been associated with asthma and atopy in some studies. Parental smoking is a consistent risk factor for childhood asthma. Secondhand smoke and ozone both stimulate TNF production. OBJECTIVES: Our goal was to investigate whether genetic variation in TNF and LTA is associated with asthma and atopy and whether the association is modified by parental smoking in a Mexican population with high ozone exposure. METHODS: We genotyped six tagging single nucleotide polymorphisms (SNPs) in TNF and LTA, including functional variants, in 596 nuclear families consisting of asthmatics 4-17 years of age and their parents in Mexico City. Atopy was determined by skin prick tests. RESULTS: The A allele of the TNF-308 SNP was associated with increased risk of asthma [relative risk (RR) = 1.54; 95% confidence interval (CI), 1.04-2.28], especially among children of non-smoking parents (RR = 2.06; 95% CI, 1.19-3.55; p for interaction = 0.09). Similarly, the A allele of the TNF-238 SNP was associated with increased asthma risk among children of nonsmoking parents (RR = 2.21; 95% CI, 1.14-4.30; p for interaction = 0.01). LTA SNPs were not associated with asthma. Haplotype analyses reflected the single SNP findings in magnitude and direction. TNF and LTA SNPs were not associated with the degree of atopy. CONCLUSIONS: Our results suggest that genetic variation in TNF may contribute to childhood asthma and that associations may be modified by parental smoking.

Complex gene-gene interactions in multiple sclerosis: a multifactorial approach reveals associations with inflammatory genes.

The complex inheritance involved in multiple sclerosis (MS) risk has been extensively investigated, but our understanding of MS genetics remains rudimentary. In this study, we explore 51 single nucleotide polymorphisms (SNPs) in 36 candidate genes from the inflammatory pathway and test for gene-gene interactions using complementary case-control, discordant sibling pair, and trio family study designs. We used a sample of 421 carefully diagnosed MS cases and 96 unrelated, healthy controls; discordant sibling pairs from 146 multiplex families; and 275 trio families. We used multifactor dimensionality reduction to explore gene-gene interactions. Based on our analyses, we have identified several statistically significant models including both main effect models and two-locus, three-locus, and four-locus epistasis models that predict MS disease risk with between approximately 61% and 85% accuracy. These results suggest that significant epistasis, or gene-gene interactions, may exist even in the absence of statistically significant individual main effects.

Variants in mannose-binding lectin and tumour necrosis factor alpha affect survival in cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis with the same mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene differ widely in survival suggesting other factors have a substantial role in mortality. OBJECTIVE: To determine if the genotype distribution of variants in three putative cystic fibrosis modifier genes (tumour necrosis factor alpha (TNFalpha), transforming growth factor beta1 (TGFbeta1) or mannose-binding lectin (MBL2)) differed among patients with cystic fibrosis grouped according to age and survival status. METHODS: Genotypes of four variants (TNFalpha-238, TNFalpha-308, TGFbeta1-509 and MBL2 O) were determined in three groups of Caucasians from a single medical centre: 101 children with cystic fibrosis (aged <17 years; mean age 9.4 years), 115 adults with cystic fibrosis (aged > or =17 years; mean age 30.8 years) and 38 non-surviving adults with cystic fibrosis (21 deceased and 17 lung transplant after 17 years of age). Genotypes of 127 healthy Caucasians in the same geographical region were used as controls. Kaplan-Meier and Cox hazard regression were used to evaluate the genotype effect on cumulative survival. RESULTS: Genotype frequencies among adults and children with cystic fibrosis differed for TNFalpha-238 (G/G vs G/A; p = 0.022) and MBL2 (A/A vs O/O; p = 0.016). When adults with cystic fibrosis were compared to non-surviving adults with cystic fibrosis, genotype frequencies of both genes differed (TNFalpha-238G/G vs G/A; p = 0.0015 and MBL2: A/A vs O/O; p = 0.009). The hazard ratio for TNFalpha-238G/G vs G/A was 0.25 (95% CI 0.06 to 1.0, p = 0.04) and for MBL2 O/O vs A/A or A/O was 2.5 (95% CI 1.3 to 4.9, p = 0.007). CONCLUSIONS: TNFalpha-238 G/A and MBL2 O/O genotypes appear to be genetic modifiers of survival of cystic fibrosis.

Linkage and association with the NOS2A locus on chromosome 17q11 in multiple sclerosis.

A large body of research supports a multifactorial cause in multiple sclerosis (MS), with an underlying genetic susceptibility likely acting in concert with undefined environmental exposures. Here, we used a highly efficient multilocus genotyping assay to study single nucleotide polymorphisms representing variation in 34 genes from inflammatory pathways in a well-characterized MS familial data set. Evidence of transmission distortion was present for several polymorphisms. Results for the NOS2A locus (exon 10 C/T, D346D) on chromosome 17q11 remained significant after correction for multiple testing and were reproduced in a second independent African American MS data set. In addition, linkage to a NOS2A promoter region polymorphism, (CCTTT)(n), was present in a third data set of multicase MS families. Our results provide strong evidence for linkage and association to a new candidate disease gene on chromosome 17q11 in MS and suggest that variation within NOS2A or a nearby locus contributes to disease susceptibility.