Prevalence and risk factors for age-related macular degeneration in an adult Japanese population: the Funagata study.

OBJECTIVE: To describe the prevalence and risk factors for age-related macular degeneration (AMD) in a Japanese population and to compare these with data from a white population. DESIGN: Population-based cross-sectional epidemiologic study. PARTICIPANTS: A population-based sample of Japanese persons 35 years or older from Funagata, Japan. METHODS: The Funagata study is a population-based study of 1758 (43% of eligible) Japanese persons 35 years or older from Funagata, Japan. In 2000 to 2002, 1625 (92.4%) participants had a nonmydriatic fundus photograph of one eye with sufficient quality for grading of AMD lesions, using the Wisconsin protocol. Age-standardized prevalence rates compared with the Blue Mountains Eye Study (BMES) population, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Risk factors were assessed by logistic regression. MAIN OUTCOME MEASURES: Early and late AMD. RESULTS: Of 1625 participants, early AMD and late AMD were present in 3.5% and 0.5%, respectively. Age-standardized early AMD prevalence in right eyes was 4.1%, similar to the corresponding prevalence of 4.4% in the BMES. For men, age-standardized prevalences of late AMD in right eyes were 1.1% and 1.2% in the BMES; for women, the corresponding prevalences were 0.3% and 2.1%, respectively. Increasing age (per 10 years; gender-adjusted OR, 2.27; 95% CI, 1.10-4.67) and current cigarette smoking (age- and gender-adjusted OR, 5.03; 95% CI, 1.00-25.47) were associated with late AMD. CONCLUSIONS: In this Japanese population, prevalence of early AMD was similar to that for whites in the BMES. Although the late AMD prevalence was lower in Japanese women, in Japanese men it was similar to that in whites. This could have resulted from the substantially high proportion of Japanese men who are smokers. Cigarette smoking and increasing age were the 2 principal factors found associated with late AMD.

Intronic single-nucleotide polymorphisms in Bcl-2 are associated with chronic obstructive pulmonary disease severity.

BACKGROUND AND OBJECTIVE: COPD is a multifactorial disease influenced by genetic and environmental factors, and gene-by-environmental interactions. There is considerable variability in the degree of airflow obstruction, moreover only 10-15% of chronic smokers develop COPD. These observations indicate that additional risk factors, possibly genetic, contribute to not only the susceptibility to COPD but also the development and severity of COPD. Recent paradigms highlight the presence and causal role of apoptosis in emphysema. There is a large amount of information on the genes involved in the regulation of apoptosis and one of the most studied is Bcl-2. The aim of this study was to investigate the genetic association of Bcl-2 gene with the level of lung function, that is, the severity, of COPD. METHODS: The genetic association of Bcl-2 polymorphisms with lung function was investigated in 261 Japanese patients with COPD using 12 single-nucleotide polymorphisms (SNPs) in Bcl-2. RESULTS: Four SNPs showed a significant association between the high and low lung function groups in a dominant trait comparison. Subsequent linkage-disequilibrium mapping and analyses of haplotype structure also showed a significant association between the level of lung function and two haplotypes comprised of the associated SNPs in Bcl-2. CONCLUSIONS: Although the linkage between Bcl-2 gene and the susceptibility to COPD remains to be clarified, the findings of the current study indicate that Bcl-2 might be influencing the level of lung function, that is, the development and severity of COPD.

Association of transforming growth factor-beta 1 functional polymorphisms with natural clearance of hepatitis C virus.

Transforming growth factor (TGF)-beta 1 suppresses the proliferation and cytotoxicity of natural killer (NK) cells, which play critical roles in resolving hepatitis C virus (HCV) infection, especially during the acute phase. We examined 230 anti-HCV antibody-positive subjects for HCV RNA and the -509T/C genotype in the TGF-beta 1 gene promoter. The -509CC genotype and the -509C allele were significantly associated with higher HCV clearance rates (P=.01) and with lower transcriptional activity. The genetic effect remained significant even after adjustment for a history of transfusion. Low TGF- beta 1 producers might have less suppression of NK cells and be more likely to resolve HCV infection.

A single nucleotide polymorphism in the CCL1 gene predicts acute exacerbations in chronic obstructive pulmonary disease.

RATIONALE: Acute exacerbations (AEs) in chronic obstructive pulmonary disease (COPD) are a major cause of morbidity and mortality in COPD. OBJECTIVES: The marked heterogeneity in the host defense mechanisms may be attributed to single nucleotide polymorphisms (SNPs) in the inflammatory chemokines that show enhanced expression in the airway of patients with COPD who experience AEs. METHODS: We investigated four SNPs of the CCL11, CCL1, and CCL5 genes in relation to the frequency and severity of AEs in retrospective and prospective studies of a cohort of 276 male patients with COPD. MEASUREMENTS AND MAIN RESULTS: In the 2-yr retrospective study , one SNP (National Center for Biotechnology Information SNP reference: rs2282691) in the predicted enhancer region of the CCL1 gene, encoding a chemotactic factor for a series of leukocytes, was significantly associated with the frequency of AEs in a dominant model (Fisher's exact test: odds ratio [OR], 2.70; 95% confidence interval [CI], 1.36-5.36; p=0.004; logistic regression: OR, 3.06; 95% CI, 1.46-6.41; p=0.003; and Kruskal-Wallis test: p=0.003). In the 30-mo prospective study, the "A" allele was a significant risk allele for the severity of AEs, with a gene-dosage effect (Kaplan-Meier method with log-rank test: AA vs. TT; log-rank statistic: 7.67, p=0.006; Cox proportional hazards regression method: OR, 5.93; 95% CI, 1.28-27.48; p=0.023). The electromobility shift assay showed that C/EBPbeta, a key transcriptional factor in response to pulmonary infections, binds to the "T" allele, but not to the "A" allele. CONCLUSIONS: Variants in the CCL1 gene are associated with susceptibility to AEs through their potential implication in the host defense mechanisms against AEs.

A novel polymorphism in secretory phospholipase A2-IID is associated with body weight loss in chronic obstructive pulmonary disease.

RATIONALE: Chronic and systemic inflammation, a potential cause of body weight loss in patients with chronic obstructive pulmonary disease (COPD), may be associated with the proinflammatory properties of secretory phospholipases A2 (sPLA2s), especially the group II subfamily sPLA2s. OBJECTIVES: We tested our hypothesis that the individual susceptibility to body weight loss in patients with COPD is attributed to the genetic variances of this sPLA2 gene region. METHODS: A total of 12 single nucleotide polymorphisms (SNPs) encompassing the sPLA2 gene region were determined in 276 male patients with COPD. MEASUREMENTS AND MAIN RESULTS: We first analyzed our patients whose body mass index (BMI) was at the bottom 100 (BMI, 17.13 +/- 1.29 kg/m2) and at the top 100 (23.83 +/- 1.98) in relation to SNPs. Both the Fisher's exact test (odds ratio, 2.36; 95% confidence interval, 1.34-4.18; p = 0.004) and logistic regression analysis (odds ratio, 2.10; 95% confidence interval, 1.13-3.90; p = 0.019) showed statistical significance between one SNP (National Center for Biotechnology Information SNP reference: rs584367) and the reduction of BMI in the recessive model in patients with COPD. Using all the patients, a significant difference between the values of BMI (log transformed) of the mutant group (CT + TT) and that of the nonmutant group (CC) of this SNP (mean [SE], 1.293 [0.005] vs. 1.317 [0.006]; p = 0.003) was found after adjustment for age, smoking habit, and pulmonary function (analysis of covariance). Importantly, this SNP caused a change in amino acids in sPLA2-IID protein (Gly80Ser). CONCLUSIONS: These results suggest that sPLA2-IID may be one of the susceptibility genes that contribute to body weight loss in patients with COPD.

Large-scale search of single nucleotide polymorphisms for hepatocellular carcinoma susceptibility genes in patients with hepatitis C.

Hepatitis C virus (HCV) infection is a major risk factor for developing hepatocellular carcinoma (HCC). The host genetic factors that are involved in the development of HCC in patients with HCV infection remain to be investigated. To search for single nucleotide polymorphisms (SNPs) in HCC susceptibility genes, 393 SNPs in 171 candidate genes were examined in 188 Japanese patients with chronic HCV infection, including 77 patients with HCC. HCC-related SNPs were then examined in another 188 patients (including 93 patients with HCC) with chronic HCV infection. Haplotype analyses of HCC-related genes were performed in a total of 376 patients. Of the 393 SNPs, 31 SNPs in 29 genes were significantly associated with HCC based on an initial screening (P < .05). Of these 31 SNPs, 3 SNPs of 3 genes (SCYB14, GFRA1, and CRHR2) were significantly associated with HCC in a secondary screening. Haplotype analyses of these 3 genes identified 2 haplotype blocks associated with HCC. In conclusion, these SNPs and haplotypes located in the SCBY14, CRHR2, and GFRA1 genes will be used as markers to identify a subgroup of Japanese patients with chronic HCV infection who are at high risk of developing HCC.

Large-scale investigation of genomic markers for severe periodontitis.

The purpose of the present study was to investigate the genomic markers for periodontitis, using large-scale single-nucleotide polymorphism (SNP) association studies comparing healthy volunteers and patients with periodontitis. Genomic DNA was obtained from 19 healthy volunteers and 22 patients with severe periodontitis, all of whom were Japanese. The subjects were genotyped at 637 SNPs in 244 genes on a large scale, using the TaqMan polymerase chain reaction (PCR) system. Statistically significant differences in allele and genotype frequencies were analyzed with Fisher's exact test. We found statistically significant differences (P < 0.01) between the healthy volunteers and patients with severe periodontitis in the following genes; gonadotropin-releasing hormone 1 (GNRH1), phosphatidylinositol 3-kinase regulatory 1 (PIK3R1), dipeptidylpeptidase 4 (DPP4), fibrinogen-like 2 (FGL2), and calcitonin receptor (CALCR). These results suggest that SNPs in the GNRH1, PIK3R1, DPP4, FGL2, and CALCR genes are genomic markers for severe periodontitis. Our findings indicate the necessity of analyzing SNPs in genes on a large scale (i.e., genome-wide approach), to identify genomic markers for periodontitis.

Large-scale search of SNPs for type 2 DM susceptibility genes in a Japanese population.

The etiology of type 2 diabetes (DM) is polygenic. We investigated here genes and polymorphisms that associate with DM in the Japanese population. Single-nucleotide polymorphisms (SNPs) of 398 derived from 120 candidate genes were examined for association with DM in a population-based case-control study. The study group consisted of 148 cases and 227 controls recruited from Funagata, Japan. No evident subpopulation structure was detected for the tested population. The association tests were conducted with standard allele positivity tables (chi(2) tests) between SNP genotype frequency and case-control status. The independent association of the SNPs from serum triglyceride levels and body mass index was examined by multiple logistic regression analysis. A value of P<0.01 was accepted as statistically significant. Six genes (met proto-oncogene, ATP-binding cassette transporter A1, fatty acid binding protein 2, LDL receptor defect C complementing, aldolase B, and sulfonylurea receptor) were shown to be associated with DM.

Genetic variations in humans associated with differences in the course of hepatitis C.

The outcome of hepatitis C virus (HCV) infection varies among individuals, but the genetic factors involved remain unknown. We conducted a population-based association study in which 238 Japanese individuals positive for anti-HCV antibody were genotyped for 269 single nucleotide polymorphisms (SNPs) in 103 candidate genes that might influence the course of infection. Altogether, 50 SNPs in 32 genes were listed. Genetic polymorphisms in IL4, IL8RB, IL10RA, PRL, ADA, NFKB1, GRAP2, CABIN1, IFNAR2, IFI27, IFI41, TNFRSF1A, ALDOB, AP1B1, SULT2B1, EGF, EGFR, TGFB1, LTBP2, and CD4 were associated with persistent viremia (P < 0.05), whereas those in IL1B, IL1RL1, IL2RB, IL12RB1, IL18R1, STAT5A, GRAP2, CABIN1, IFNAR1, Mx1, BMP8, FGL1, LTBP2, CD34, and CD80 were associated with different serum alanine aminotransferase levels in HCV carriers (P < 0.05). The sorted genes allow us to draw novel hypotheses for future studies of HCV infection to ultimately identify bona fide genes and their variations.

Single nucleotide polymorphisms associated with aggressive periodontitis and severe chronic periodontitis in Japanese.

Periodontitis is a common inflammatory disease causing destruction of periodontal tissues. It is a multifactor disease involving genetic factors and oral environmental factors. To determine genetic risk factors associated with aggressive periodontitis or severe chronic periodontitis, single nucleotide polymorphisms (SNPs) in multiple candidate genes were investigated in Japanese. We studied 134 patients with aggressive periodontitis, 117 patients with severe chronic periodontitis, and 125 healthy volunteers without periodontitis, under case-control setting, and 310 SNPs in 125 candidate genes were genotyped. Association evaluation by Fisher's exact test (p < 0.01) revealed statistically significant SNPs in multiple genes, not only in inflammatory mediators (IL6ST and PTGDS, associated with aggressive periodontitis; and CTSD, associated with severe chronic periodontitis), but also in structural factors of periodontal tissues (COL4A1, COL1A1, and KRT23, associated with aggressive periodontitis; and HSPG2, COL17A1, and EGF, associated with severe chronic periodontitis). These appear to be good candidates as genetic factors for future study.