Association of genetic polymorphisms with erythrocyte traits: Verification of SNPs reported in a previous GWAS in a Japanese population.

Erythrocyte count and volume are the commonly used hematological indices for anemia that change in various diseases. To date, however, only one study ever exists that addressed erythrocyte trait-associated single nucleotide polymorphisms (SNPs) in a Japanese population. Because that study was performed in patients with various diseases, we confirmed the reported associations in a general population. Participants in the current study were from the Shizuoka component of the Japan Multi-Institutional Collaborative Cohort Study, which included 4971 men and women aged 35 to 69years who were recruited between 2006 and 2007. We analyzed the association of seven selected SNPs with the following erythrocyte traits: red blood cell count, hemoglobin (Hb) and hematocrit (Ht) levels, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. The erythrocyte traits were regressed on a number of minor alleles of selected SNPs. Then we compared our findings with those from a genome-wide association study performed in a Japanese population. We replicated the association of ABO rs495828, PDGFRA-KIT rs218237, USP49-MED20-BSYL-CCND3 rs3218097, C6orf182-CD164 rs11966072, TERT rs2736100, and TMPRSS6 rs5756504 with erythrocyte traits in our independent Japanese population. In addition, we found a significant interaction between TERT rs2736100 and smoking habit that affected Hb and Ht levels.

Matrix metalloproteinase 9 gene polymorphisms are associated with a multiple family history of gastric cancer.

BACKGROUND: A family history of gastric cancer (GC) is a well-known risk factor of GC. Genetic variations in genes of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been related to the risk of GC, but their association with familial background is not clear. We investigated whether individuals with a multiple family history of GC have more risk genotypes of MMP/TIMP genes. METHODS: We genotyped ten common functional polymorphisms of MMP/TIMP genes in 4427 individuals aged 35-69 years without a history of GC who were enrolled in the Japan Multi-institutional Collaborative Cohort Study. Individuals who have two or more first-degree relatives (parents and siblings) with GC were categorized as having a multiple family history. Odds ratios (ORs) for multiple family history compared with no family history were calculated. RESULTS: MMP9 279QQ (rs17576) was more frequently observed in individuals whose both parents had a history of GC (n = 23) and in individuals for whom one parent and their sibling(s) had a history of GC (n = 36) compared with those with no family history (n = 3816) [30.4 % vs 11.6 %, OR 4.34, 95 % confidence interval (CI) 1.45-13.03 and 16.7 % vs 11.6 %, OR 2.26, 95 % CI 0.81-6.27 after adjustment for age, sex, and current smoking]. The population attributable fraction was 38.1 %. The haplotype MMP9-1562C/279Q/668Q was more frequently observed in individuals whose both parents had a history of GC and in individuals for whom one parent and their sibling(s) had a history of GC compared with those with no family history (OR 3.35, 95 % CI 0.75-14.96 and OR 3.51, 95 % CI 1.35-9.15 respectively). CONCLUSIONS: MMP9 polymorphisms were associated with a multiple family history of GC. Screening for these genotypes together with familial background may help us to identify individuals at an increased risk of GC.

Metallothionein MT2A A-5G Polymorphism as a Risk Factor for Chronic Kidney Disease and Diabetes: Cross-Sectional and Cohort Studies.

Metallothioneins (MTs) are proteins that protect cells from toxic agents such as heavy metal ions or reactive oxygen species. MT2A A-5G is a single nucleotide polymorphism in the promoter region of the MT2A gene, and the minor G allele results in lower transcription efficiency. We aimed to elucidate associations between MT2A A-5G and risks of 2 diseases potentially related to lowered MT expression, chronic kidney disease (CKD), and diabetes mellitus (DM), in a community-dwelling population. Study subjects were Nagoya city residents participating in the Japan Multi-Institutional Collaborative Cohort Study (J-MICC) Daiko Study, comprised 749 men and 2,025 women, aged 39-75 years. CKD (>stage 3) and DM were defined by standard guidelines. Associations were evaluated using logistic regression models with adjustments for age, sex and potential confounders in a cross-sectional study, and verified in a 5-year longitudinal study. Odds ratios (OR [95% confidence interval]) were calculated relative to the AA genotype. Serum MT (I + II), Cd and zinc levels were also determined by genotype. The OR of the GG genotype for CKD risk was 3.98 (1.50, 10.58) in the cross-sectional study and 5.17 (1.39, 19.28) in the longitudinal study. The OR of the GA genotype for DM was 1.86 (1.26, 2.75) in the cross-sectional study and 2.03 (1.19, 3.46) in the longitudinal study. MT2A A-5G may be associated with CKD and DM risks. This polymorphism is a promising target for evaluations of CKD and DM risks with possible involvement of low-dose chronic exposure to environmental pollutants.