Polymorphisms in Turkish population

Department of Medical Biology, Faculty of Medicine, Suleyman Demirel University, 32260 Cunur, Isparta, Turkey, nilufersahin@yahoo.com.

Mutations in the ganglioside-induced differentiation-associated protein 1 gene (GDAP1) cause Charcot-Marie-Tooth type 2 (CMT2), a severe autosomal recessive form of neuropathy associated with axonal phenotypes. It has been screened in this study for the presence of mutations in the coding region of GDAP1, which maps to chromosome 8q21, in a family with CMT2. To date, 29 mutations in the GDAP1 have been reported in patients of different ethnic origins. Here, we report a novel missense mutation (c.836A>G), and two polymorphisms: a silent variant (c.102G>C), and a 5′-splice site mutation (IVS5+24C>T) in GDPA1 gene identified in a five generation Turkish family with autosomal recessive CMT2.

Molecular Medicine Laboratory, Department of Pediatrics, Faculty of Medicine, Ege University, Izmir, Turkey.

Angiotensin converting enzyme (ACE) plays an essential role in the renin-angiotensin system. It converts angiotensin I to angiotensin II and inactivates bradykinin and tachykinins. Numerous studies have been published investigating associations of the ACE gene I/D polymorphism with various pathophysiological conditions. We examined the prevalence of the ACE I/D polymorphism in a sample of healthy volunteers from western Turkey, including 1063 healthy Turkish controls. Analysis of the ACE I/D gene polymorphisms by polymerase chain reaction found frequencies of 16.1% for the II genotype, 47.7% for the ID genotype, and 36.2% for the DD genotype. The allele frequency was 39.9% for the I alleles and 60.1% for the D allele. This study demonstrates that the allele and genotype frequency values for the Turkish population are similar to previously published frequencies for Caucasian populations.

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.