Polymorphisms in Turkish population

Faculty of Medicine, Department of Medical Biology, Harran University, Sanliurfa, Turkey.

Type 2 diabetes mellitus (T2DM) is by far the most common type of diabetes and is characterized by insulin resistance and altered insulin secretion. Some genes, such as the vitamin D receptor gene (VDR, NM_001017535; GI: 7421), involved in its metabolic pathway have been regarded as good candidates for T2DM. In this study, we investigated whether there was an association of VDR: g.59979G>T or c.1025-49G>T (ApaIG>T) and g.60058T>C or c.1056T>C (TaqIT>C) polymorphisms in the 3′ untranslated region of VDR with T2DM in a Turkish population. We collected blood samples from 241 individuals (72 patients with T2DM and 169 healthy individuals), and their DNA was isolated. Polymorphisms of the VDR were analyzed by DNA amplification with polymerase chain reaction and endonuclease digestion with ApaI and TaqI. Body mass index was higher in T2DM patients than in control individuals. However, the frequency of g.59979TT genotype in T2DM patients was not significantly increased compared to healthy subjects (37.5% vs. 36.1%, respectively). Although the VDR g.60058CC genotype in T2DM patients (19.4%) was higher than that in healthy individuals (11.2%), there was no significant difference. In the same way, there was no difference between the groups in allele frequencies. In conclusion, our study did not provide evidence for the association of two examined VDR polymorphisms with T2DM in a Turkish population.

Department of Medical Biology and Genetics, Gazi University Faculty of Medicine, Besevler, Ankara, Turkey.

Obesity is a complex disease caused by both genetics and environmental factors. Melanocortin-4 receptor (MC4R) (MIM 155541) gene polymorphisms were reported to be the cause of monogenic obesity in humans. We studied three polymorphisms (Val50Met, Val103Ile, and Ser58Cys) and a mutation (Asn274Ser) of the MC4R gene in 203 obese patients and in 110 healthy subjects in the Turkish population. A high incidence of Val103Ile and Val50Met polymorphisms as well as the Asn274Ser mutation was found in the obese patients, whereas no significant correlation was found regarding the Ser58Cys polymorphism. We conclude that there is a concordance between the polymorphisms (Val103Ile, Val50Met, Ser58Cys) that were first studied in the Turkish population with obesity.

Department of Periodontology, School of Dentistry, Ege University, Izmir, Turkey. ali.gurkan@ege.edu.tr

AIM: Evidence suggests that the ultimate product of the renin-angiotensin system (RAS), angiotensin II, exerts inflammatory actions. The present study aimed to evaluate the inter-relation between gene polymorphisms of the RAS components; angiotensin converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type-I receptor (AT1R), and severe chronic periodontitis (CP). MATERIAL AND METHODS: DNA was obtained from peripheral blood of 90 CP patients and 126 periodontally healthy subjects, and the clinical parameters were recorded. ACE I/D, AGT M235T and AT1R A1166C polymorphisms were genotyped by the PCR-RFLP method. Chi-square, anova and logistic regression methods were used in statistical analyses. RESULTS: The frequency of the ACE D allele was significantly lower in the CP group than the healthy group (p(corr)=0.015). CP subjects exhibited increased C allele carriage and C allele frequency of the AT1R gene (p(corr)=0.03 and p(corr)=0.03, respectively). All clinical parameters of CP patients were found to be similar in variant allele-carrying and non-carrying subjects (p>0.05). CONCLUSIONS: The present findings suggest that ACE I/D and AT1R polymorphisms might be associated with susceptibility to CP but not with disease severity. The D allele of ACE I/D might be associated with decreased, whereas the C variant of AT1R A1166C might be associated with an elevated risk for CP in Turkish population.

1Department of Urology, Bezm-i Alem Valide Sultan Vakif Gureba Research and Education Hospital, Istanbul 34095, Tukey.

We evaluated the genotypes of the serotonin transporter gene (5-HTT) in patients with premature ejaculation (PE) to determine the role of genetic factors in the etiopathogenesis of PE and possibly to identify the patient subgroups. A total of 70 PE patients and 70 controls were included in this study. All men were heterosexual, had no other disorders and were either married or in a stable relationship. PE was defined as ejaculation that occurred within 1 min of vaginal intromission. Genomic DNA from patients and controls was analyzed using polymere chain reaction, and allelic variations of the promoter region of the serotonin transporter gene (5-HTTLPR) were determined. The 5-HTTLPR (serotonin transporter promoter gene) genotypes in PE patients vs. controls were distributed as follows: L/L 16% vs. 17%, L/S 30% vs. 53% and S/S 54% vs. 28%. We examined the haplotype analysis for three polymorphisms of the 5-HTTLPR gene: LL, LS and SS. The appropriateness of the allele frequencies in the 5-HTTLPR gene was analyzed by the Hardy-Weinberg equilibrium using the chi(2)-test. The short (S) allele of the 5-HTTLPR gene was significantly more frequent in PE patients than in controls (P < 0.05). We suggest that the 5-HTTLPR gene plays a role in the pathophysiology of all primary PE cases. Further studies are needed to evaluate the relationship between 5-HTTLPR gene polymorphism and patient subgroup (such as primary and secondary PE) responses to selective serotonin reuptake inhibitors as well as ethnic differences.Asian Journal of Andrology advance online publication, 2 March 2009; doi: 10.1038/aja.2008.3.