Nilgun Sallakci

TNF-α gene 1031 T/C polymorphism in Turkish patients with Behçet's disease

Background  Genetic factors that predispose individuals to Behçets disease (BD) are considered to play an important role in development of the disease. The tumour necrosis factor (TNF)‐α gene, which is closely linked to the HLA‐B51 gene, is involved in susceptibility for BD. Recently, a polymorphism at position −1031 within the TNF‐α promoter region was demonstrated to be responsible for susceptibility to BD in a British population. However, the functional effects of this polymorphism have not yet been determined.

Specific interleukin‐1 gene polymorphisms in Turkish patients with Behçet's disease

Abstract:  Genetic factors that predispose individuals to Behçets disease (BD) are considered to play important roles in the development of the disease. The pro‐inflammatory cytokine interleukin‐1 (IL‐1) has been implicated in the pathogenesis of BD. Our aim was to determine a possible association of specific polymorphisms of IL‐1α, IL‐1β, and IL‐1 receptor antagonist genes with susceptibility for BD. We genotyped 72 patients with BD and 163 healthy controls for IL‐1α−889, IL‐1β−511, and +3953 (nt5887) single‐nucleotide polymorphisms besides IL‐1 receptor antagonist variable number of tandem repeat polymorphism (for five different alleles). Comparison of the IL‐1β+3953 T allele and TT genotype frequencies showed a significant difference between patients with BD and controls (54.2 vs. 40.5%, OR = 1.74, P = 0.024, and 40.3 vs. 19.6%, OR = 2.76, P = 0.009, respectively). However, no difference was observed in the genotype or allele frequencies of IL‐1α−889, IL‐1β−511, and IL‐1 receptor antagonist between the patients with BD and the controls. Our results indicate that susceptibility to BD is increased in individuals carrying the IL‐1β+3953 T allele and TT genotype.

VEGF polymorphisms and serum VEGF levels in Parkinson's disease

Accumulated data within the recent years demonstrate that reduced levels of VEGF which is a well known angiogenic molecule might cause neurodegeneration in part by impairing neural tissue perfusion, vasoregulation and normal functioning of perivascular autonomic nerves. Additionally, VEGF has been reported to support neuroprotection in dopaminergic neurons by indirect and direct mechanisms and suppress apoptosis in dopaminergic neurons in vitro. The aim of the current study is first to demonstrate whether there is an association between the three common VEGF polymorphisms (-2578C/A, -634C/G and 936C/T) in the VEGF gene and idiopathic Parkinsons disease (IPD) which is a neurodegenerative disease caused by the progressive degeneration of nigrostriatal dopaminergic neurons, and second to see if the serum levels of VEGF is reduced in the patients with IPD. We screened the genotype and allele frequencies of three common functional polymorphisms of VEGF, namely -2578C/A, -634C/G and 936C/T in DNA samples of 126 patients with IPD and healthy control subjects and also we compared the median serum levels of VEGF between these two groups. No association was found between the inspected VEGF polymorphisms and IPD and also no difference was found between the serum VEGF levels of both groups. The current study failed to support the hypothesis that VEGF polymorphisms and/or reduced serum VEGF levels are likely contributors to the neurodegenerative process in IPD.

Human leukocyte antigens class I and class II in patients with pemphigus in southern Turkey

Background  Genetic factors that predispose individuals to pemphigus are considered to play important roles in the development of the disease. Furthermore, population studies of patients with pemphigus have clearly shown that the most prevalent alleles differ across ethnic groups.

The influence of CTLA-4 single nucleotide polymorphisms on acute kidney allograft rejection in Turkish patients.

Cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) is a cell surface protein, which down‐regulates the immune response at CTLA‐4/CD28/B7 pathway. We aimed to investigate the influence of the −318C/T, +49A/G, −1661A/G and CT60A/G, and CTLA‐4 gene polymorphisms on acute rejection of kidney allograft in Turkish patients. The study design was a case–control study that consists of three groups: Group 1 (n = 34) represented the kidney transplant (Ktx) recipients who experienced acute rejection, Group 2 (n = 47) was randomly assigned Ktx recipients without acute rejection, and Group 3 (n = 50) consisting of healthy volunteers to evaluate the normal genomic distribution. The polymerase chain reaction–restriction fragment length polymorphism technique was used to determine the polymorphisms. Genotype and allele frequencies among three groups denoted similar distributions for +49A/G, −1661A/G, and CT60A/G. Conversely, −318C/T genotype was three times more frequent in the acute rejection group than in the non‐rejection group (OR = 3.45; 95%CI = 1.18–10.1, p = 0.015) and two times more frequent than the healthy control group (OR = 2.45; 95% CI = 0.98 – 6.11, p = 0.047). Additionally, having a T allele at −318 position was significantly associated with acute rejection (0.147 vs. 0.043, OR = 3.45; 95% CI = 1.13–10.56, p = 0.02). 318C/T gene polymorphism and T allelic variant were found to be associated with increased acute rejection risk in Turkish kidney allograft recipients.

Interleukin-12 (-1188) A/C and interferon-γ (+874) A/T gene polymorphisms in subacute sclerosing panencephalitis patients.

The two polymorphisms [IL-12 (-1188) A/C and the IFN-γ (+874) A/T)] are known to have functional consequences and henceforth were analyzed in subacute sclerosing panencephalitis (SSPE) patients to reveal a possible relation with these polymorphisms and this debilitating disease. For the IL-12 (-1188) A/C polymorphism, 78 patients and 90 healthy individuals were analyzed. An increase in the AA genotype was determined (p = 0.02, OR = 2.06). There was also a statistically significant difference between the control group and the patients with respect to the allele frequencies (p = 0.04, OR = 1.65). For the IFN-γ (+874) A/T polymorphism, 69 SSPE patients and 115 controls were studied and there was not a significant difference between the two groups. Our findings suggested that not the IFN-γ (+874) A/T but the IL-12 (-1188) A/C polymorphism is correlated with SSPE and having an AA genotype or A allele decreases the risk of developing SSPE by 2.06- and 1.65-fold, respectively.