Polymorphisms in Turkish population

Gazi University, Faculty of Medicine.

Genetic and environmental factors are involved in Prostate Cancer (PCa) etiology. Single nucleotide polymorphisms (SNPs) may contribute to the PCa pathogenesis. The goal of this study is to determine the role of vitamin D receptor (VDR) gene polymorphisms and haplotypes in the development and progression of sporadic PCa. One hundred and thirty-three PCa patients and one hundred and fifty-seven age-matched healthy controls were genotyped for the ApaI (rs7975232), BsmI (rs1544410) and TaqI (rs731236) polymorphisms in VDR gene by using polymerase chain reaction-restriction fragment length polymorphism. An association was observed between the ApaI polymorphism and PCa predisposition (P = 0.03). When compared with AA genotype, there was a highly notable difference in the frequencies of the Aa (P = 0.02), aa (P = 0.026) and ApaI “a” allele carriers (Aa+aa) (P = 0.009) genotypes. Furthermore, we found a statistical difference in the allele frequencies of the ApaI polymorphism between the sporadic PCa patients and control subjects (P = 0.013). The genotype distribution for the BsmI and TaqI polymorphisms were similar between cases and controls (P >0.05). No clinically significant relationship was found between the three-locus haplotypes and development of sporadic PCa. The genotype frequencies for the three polymorphisms of the VDR gene within subgroups of PCa (defined by tumor stage, Gleason score, PSA levels) were also analyzed, but no statistically noteworthy difference was observed (P >0.05). As far as we know, this is the first study which investigates the relationship between VDR genotypes and sporadic PCa in the Turkish Population. Our findings suggest that the VDR ApaI (rs7975232) polymorphism may play a role in the development of sporadic PCa.

Institute of Clinical Pharmacology, Charité-Universitätsmedizin Berlin, Humboldt University of Berlin, Schumannstrasse 20/21, 10098 Berlin, Germany.

BACKGROUND: OATP1B1 is one of the key hepatocellular uptake transporters providing extraction of diverse compounds, including bile acids, xenobiotics, and a variety of drugs, from portal venous blood into the liver. Polymorphisms of the SLCO1B1 gene have been demonstrated to influence in vitro transport function and the pharmacokinetic profile of compounds. OBJECTIVE: The goal of our study was the comparison of SLCO1B1 gene sequence variability in three ethnic groups as a basis for future genetic association studies. METHODS: Eighteen exonic SLCO1B1 single nucleotide polymorphisms (SNPs) were genotyped by PCR and RFLP analysis in 300 German, 94 Turkish, and 115 African subjects. Calculation of pairwise linkage disequilibrium and estimation of population haplotype frequencies were carried out, and haplotype block structure was determined. RESULTS: Only eight genotyped SNPs (c.388A>G, c.411G>A, c.463C>A, c.521T>C, c.571C>T, c.597C>T, c.1463G>>C, c.1929A>C) were found in at least one of our German, Turkish, or African samples. A total of 12 haplotypes with a frequency >or=1% in at least one of the three populations could be inferred. Between the Caucasian and African samples, significant differences in sequence variability were observed leading to a different haplotype profile in these populations. CONCLUSION: Our results demonstrate a high sequence variability of OATP1B1 within different popuations. In the future, distinct haplotypes should be taken into account when studying the effect of OATP1B1 on drugs in different populations.

Department of Oral Biology and Center for Craniofacial and Dental Genetics, School of Dental Medicine, University of Pittsburgh, Pittsbergh, PA 15261, USA. arv11@dental.pitt.edu

Recently, the IRF6 contribution that was reported for Van der Woude syndrome and non-syndromic oral clefts was extended to isolated tooth agenesis. Here we report the first study that tries to replicate this finding and we provide further evidence that IRF6 contributes to isolated tooth agenesis. Fifty-two sporadic tooth agenesis cases and their parents were studied. DNA samples were obtained from whole blood or saliva samples. Genotyping was performed by TaqMan assays. Linkage disequilibrium analysis and transmission distortion of the marker alleles were performed. A haplotype involving the most 5′IRF6 markers was associated with sporadic tooth agenesis (p=0.006). An association could still be seen when only cases with at least one missing incisor (p=0.01) and cases with at least one missing premolar (p=0.004) were included in the analysis.

Department of Medical Biology and Genetics, Faculty of Medicine, Ondokuz Mayis University, 55139, Samsun, Turkey.

Genetic differences in the metabolism of xenobiotics have recently been suggested as modifiers of individual susceptibility to bladder cancer (BC). The objective of this study was to investigate the relationship between bladder tumor and variants of cytochrome p450 1A2 (CYP1A2) 734 C –> A, cytochrome p450 2D6 (CYP2D6) 1934 G –> A, glutathione S-transferase M1, (GSTM1 null), glutathione S-transferase T1 (GSTT1 null), and glutathione S-transferase P1 (GSTP1) I105 V. We investigated the distribution of these polymorphisms in 135 BC patients and in 128 age and sex-matched cancer-free controls. The polymorphisms were analyzed using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay and the multiplex PCR method. Genotype and allele frequencies and their associations with BC risk, demographic factors, smoking status, and tumor stage were investigated. The prevalence of GSTT1 null genotype in cases was 23%, compared with 7% in the control group (OR = 3.94, 95% CI = 1.70-9.38, P = 0.001). There was no association between the studied polymorphisms of CYP1A2, CYP2D6, GSTM1, and GSTP1 genes and BC. There was an association between smoking status and BC. These data seem to indicate that GSTT1 gene polymorphism may be associated with BC in the Turkish population studied. Further studies will be needed to clarify the role of such variation in determining susceptibility to BC.