Polymorphisms in Turkish population

Abstract

BACKGROUND: Breast cancer (BC), is more prevalent in subjects who have had prolonged exposure to heterocyclic amines, aromatic amines and high levels of oestradiol. Cytochrome P450 1B1 (CYP1B1) and N-acetyltransferase2 (NAT2) have complementary role in metabolism of xenobiotics such as arylamines and heterocyclic amines, CYP1B1 also hyroxylates 17-beta oestradiol. CYP1B1*3 polymorphism and seven missense and four silent polymorphisms of NAT2 were investigated.

PATIENTS AND METHODS: Sixty Turkish female BC patients and 103 healthy controls were phenotyped by polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP). Results and

CONCLUSION: The distribution of NAT2 activity in the healthy control group was found to be correlated with that of healthy caucasians. Patients had slow acetylator phenotypes of NAT2, 1.8 times higher than controls but no statistical differences were found (p=0.07). In addition, the NAT2*5 alelle was more statistically correlated with breast cancer patients rather than the controls (p=0.02). Moreover, NAT2*5B was the most frequent haplotype of the NAT2*5 family (p=0.000). Breast cancer patients were detected to posses more CYP1B1*3 mutant alleles than the controls (p=0.043). The combined effect of CYP1B1*3 polymorphism and NAT2 slow acetylator genotype contributed to an increased risk for breast cancer in patients in this study (p=0.004).

Abstract

The -219G/T (rs405509) and +113G/C (rs440446) polymorphisms within the regulatory region of the apolipoprotein E (APOE) gene have been related to the transcriptional activity of the gene. We examined the effect of the stated polymorphisms and their construct haplotypes with the APOE varepsilon2/varepsilon3/varepsilon4 polymorphism on lipid levels and insulin resistance in the Turkish Adult Risk Factor Study. Randomly selected 1774 adults (mean age, 55.0 +/- 11.7 years; 51.2% women) participating in the population-based Turkish Adult Risk Factor Study were cross-sectionally analyzed for the -219G/T, +113G/C, and varepsilon2/varepsilon3/varepsilon4 polymorphisms as well as their haplotypes. Insulin resistance was defined as the 70th percentile in the sample (>2.51) of the homeostatic model assessment (HOMA). The frequencies of the -219T and +113C alleles were 0.477 and 0.423, respectively; and those of haplotype 1 (GGvarepsilon3) and haplotype 2 (TCvarepsilon3) were 44.1% and 41.9%, respectively. The -219G/T and +113G/C genotypes (both P < .04) and diplotypes of haplotype 2 (TCvarepsilon3) (P < .014) were inversely related to serum fasting insulin and the HOMA index, even after controlling for 8 relevant covariates, but not to serum lipids. Within the APOE3 group, haplotype 2 (TC-/TC+) heterozygotes had an odds ratio of 0.66 (95% confidence interval, 0.42-0.99) for HOMA of insulin resistance after adjusting for 8 covariates. APOE promoter polymorphisms and their diplotypes are independently related with serum fasting insulin levels and HOMA index among Turks.

Abstract

BACKGROUND AND AIMS: Increased synthesis of several urinary proteins including osteopontin (OPN) has been shown to be associated with stone formation within the urinary tract. The objective of this study was to analyze the genotype distributions and allele frequencies for OPN gene promoter T-593A and C6982T (in exon 7) polymorphisms among patients with kidney stones.

METHODS: In this case-control study, the study group consisted of 121 patients with radiologically confirmed nephrolithiasis. Genomic DNA from patients and control cases (n = 100) was analyzed by single-strand conformation polymorphism method and nucleotide sequence analysis.

RESULTS: Homozygous carriers of the T-593T genotype were more frequent, but carriers of the A-593A genotype were less frequent in patients than in controls. There was also an increase in -593T allele (88% in patients vs. 79% in controls) and decrease in -593A allele frequencies (21% in control vs. 12% in patients) in the nephrolithiasis groups (p = 0.013). The carriers of C6982C genotype were less frequent, but marked increases in T6982T genotype (25.6% in patients vs. 7% in controls, p = 0.001) and 6982T allele frequency (53.3% in patients vs. 37.5% in controls, p = 0.001) were noted in patients of Turkish ancestry.

CONCLUSIONS: These results are the first to demonstrate the existence of T-593A promoter polymorphism of the OPN gene and significant association with risk of developing nephrolithiasis. Our results showed marked associations between polymorphisms (C6982T and T-593A) of the OPN gene and the stone-forming phenotypes in the Turkish population.