Polymorphisms in Turkish population

Department of Periodontology, Faculty of Dentistry, Baskent University, Ankara, Turkey. esragd@yahoo.com

Localized aggressive periodontitis (LAgP) is a complex multifactorial periodontal disease to which genetic factors are thought to predispose individuals. Interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) are potent immunomodulators and proinflammatory cytokines that have been implicated in the pathogenesis of autoimmune and infectious diseases and proposed to be risk factors for LAgP. Our aim was to investigate IL-1 alpha (+4845), IL-1 beta (+3954), and TNF-alpha (-308) gene polymorphisms in Turkish LAgP patients. We genotyped 31 LAgP patients and 31 healthy controls for IL-1alpha(+4845), IL-1beta(+3954), and TNF-alpha(-308) using standard PCR amplification followed by restriction enzyme digestion and gel electrophoresis. Higher prevalence of heterozygosity for IL-1alpha(+4845) was found in cases (65%) when compared to controls (35%) (P < 0.05). While homozygous allele 1 of IL-1beta(+3954) was the most frequent genotype in cases (62%), no controls were homozygous for this allele (P < 0.001). Homozygous allele 1 was the most common TNF-alpha genotype in both groups, however no significant difference in TNF-alpha genotypes was found between groups. In conclusion, in this Turkish population, susceptibility to LAgP is increased by heterozygosity for allele 1 of IL-1alpha(+4845) or homozygosity for allele 1 of IL-1beta(R+3954). Moreover, IL-1 gene polymorphisms appear to have a role in susceptibility to LAgP, and the above-mentioned genotypes could be an important risk factor for LAgP in the Turkish population.

Department of Dermatology, School of Medicine, Mersin University, Mersin, 33079, Turkey, drkbaz@hotmail.com.

Acne is a multifactorial, chronic inflammatory disease of pilosebaceous unit in which cytokines have been implicated in the pathogenesis. Although it is thought to be an inherited disease, there are limited data supporting the relevant genetic elements. Tumor necrosis factor-alpha (TNF-alpha) is one of the proinflammatory cytokines involved in the acne pathogenesis. Several single-nucleotide polymorphisms (SNPs) have been identified in the human TNF-alpha gene promoter. The polymorphism at position -308, which involves substituting guanine (G) for adenine (A) (TNFA-308 G/A) has been linked to increased susceptibility to several chronic inflammatory diseases. The aim of this study was to determine the TNFA-308 G/A polymorphism in acne and to examine whether there is a relationship between this polymorphism and disease susceptibility. Exactly, 113 patients with acne and 114 healthy control subjects were included in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used for analysis of the TNFA-308 G/A polymorphism. We found that the frequency of the TNFA-308 GA genotype was statistically significantly increased in patients compared with healthy controls (P < 0.001). There was no association between TNFA genotypes and severity of acne (P > 0.05). There was also no significant difference between male and female patients. Our results suggest that TNFA-308 G/A polymorphism may contribute to a predisposition to acne in Turkish population.