Akin Tekcan

IL-4 and MTHFR gene polymorphism in rheumatoid arthritis and their effects.

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that mainly affects the joints. Polymorphic variations of the cytokine genes and MTHFR gene have received attention as potential markers of susceptibility, severity, and/or protection in RA. The aim of this study was to investigate the MTHFR C677T and IL-4 70bp VNTR variation in Turkish patients with RA and evaluate if there was an association with clinical features, especially ocular involvement, in RA patients. The study included 297 persons (147 patients with RA and 150 healthy controls). Genomic DNA was isolated and genotyped using PCR assay for the MTHFR gene C677T and IL-4 gene 70bp VNTR polymorphisms. Our results show that there was statistically significant difference between the groups with respect to IL-4 genotype (p=0.01) and allele frequencies (p<0.002). There was no statistical significant difference in the genotype frequencies MTHFR gene, but allele frequencies showed statistically significant association (p=0.01). When we examined MTHFR and IL-4 genotype frequencies according to the clinical characteristics, we found that there was a difference between MTHFR genotypes and ocular involvement but it is not to a statistical significant degree (p=0.09). In the combined genotype analysis, MTHFR/IL-4 CCP2P2 combine genotype was estimated to have protective effect against RA, CTP1P2 combine genotype was found to be risk for RA. Our findings suggest that there is an association of IL-4 gene 70bp VNTR polymorphism and MTHFR C677T polymorphism with susceptibility of a person for development of RA.

Investigation of associations between obesity and LEP G2548A and LEPR 668A/G polymorphisms in a Turkish population.

Objective. Obesity is a complex heterogeneous disease that is caused by genes, environmental factors, and the interaction between the two. The leptin (LEP) and leptin receptor (LEPR) genes have been evaluated for polymorphisms that could potentially be related to the pathophysiology of obesity and its complications. The aim of this study was to investigate the role of LEP G2548A and LEPR 668A/G polymorphisms in the pathogenesis of obesity. Subjects. The study included 127 patients with obesity and 105 healthy controls. Polymerase chain reaction and restriction fragment length analysis for LEP G2548A and LEPR 668A/G polymorphisms were applied. Results. There was no statistically significant difference in the genotype frequencies of the LEP gene polymorphism between patients and control groups (P > 0.05). We found a difference in the LEPR genotypes between patients and controls, but this was not statistically significant (P = 0.05). Additionally, we found an increased risk of obesity in the LEP/LEPR GG/GG combined genotype (P < 0.05). Conclusion. Our findings indicate that the LEP G2548A polymorphism is not a relevant obesity marker and that the LEPR 668A/G polymorphism may be related to obesity in a Turkish population. Further researches with larger patient population are necessary to ascertain the implications of LEP and LEPR polymorphisms in obesity.

Significant association of interleukin-4 gene intron 3 VNTR polymorphism with susceptibility to knee osteoarthritis.

OBJECTIVE Interleukin-4 (IL-4) is a strong chondroprotective cytokine and polymorphisms within this gene may be a risk factor for osteoarthritis (OA). We aimed to investigate genotype and allele frequencies of IL-4 gene intron 3 variable number of tandem repeats (VNTR) polymorphism in patients with knee OA in a Turkish population. METHODS The study included 202 patients with knee OA and 180 healthy controls. Genomic DNA was isolated and IL-4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers followed by restriction fragment length polymorphism (RFLP) analysis. RESULTS Our result show that there was statistically significant difference between knee OA patients and control group with respect to IL-4 genotype distribution and allele frequencies (p=0.000, OR: 0.20, 95% CI: 0.10-0.41, OR: 0.22, 95% CI: 0.12-0.42, respectively). CONCLUSIONS Our findings suggest that there is an association of IL-4 gene intron 3 VNTR polymorphism with susceptibility of a person for development of knee OA. As a result, IL-4 gene intron 3 VNTR polymorphism could be a genetic marker in OA in a Turkish study population. This is the first association study that evaluates the associations between IL-4 gene VNTR polymorphism and knee OA.

Association between fibromyalgia syndrome and polymorphism of the IL-4 gene in a Turkish population.

PURPOSE Fibromyalgia (FM) syndrome is a form of non-articular rheumatism characterized by long term and widespread musculoskeletal pain, morning stiffness, sleep disturbance, paresthesia, and pressure hyperalgesia at characteristic sites, called soft tissue tender points. The etiology of FM is still obscure. Genetic factors may predispose individuals to FM. Cytokines may play a role in the pathophysiology of FM. The aim of this study was to investigate the interleukin-4 (IL-4) 70 bp VNTR variations in Turkish patients with FM and evaluate if there was an association with clinical features, especially between these polymorphisms. METHODS The study included 300 patients with FM and 270 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) for the IL-4 gene 70 bp VNTR polymorphisms. RESULTS There was statistically significant difference between the groups with respect to IL-4 genotype distribution and allele frequencies (p<0.0001). The homozygous P1P1 genotype and P1 allele were significantly higher in FM patients than in healthy controls (p=0.04; OR: 3.25, 95% CI: 1-10, p<0.0001; OR:4.84, 95% CI:3-7.7). There was not any difference between the groups respect to IL-4 genotype distribution and allele frequencies (p>0.05) and clinical characteristics. CONCLUSION Our findings suggest that there is an association of IL-4 gene 70 bp VNTR polymorphism with susceptibility of a person for development of FM. As a result, further studies are necessary to determine whether IL-4 may be a genetic marker for FM in the Turkish population.

The role of IL-4 gene 70 bp VNTR and ACE gene I/D variants in Familial Mediterranean fever

Familial Mediterranean fever (FMF) is characterized by recurrent attacks of fever and inflammation in the peritoneum, synovium, or pleura, accompanied by pain. It is an autosomal recessive disease caused by mutations in the MEFV (MEditerranean FeVer) gene. Patients with similar genotypes exhibit phenotypic diversity. As a result, the variations in different genes could be responsible for the clinical findings of this disease. In previous studies genes encoding Angiotensin-Converting Enzyme (ACE) and IL-4 (Interleukin-4) were found to be associated with rheumatologic and autoimmune diseases. In the present study we hypothesized whether ACE I/D or IL-4 70 bp variable tandem repeats (VNTR) genes are associated with FMF and its clinical findings in Turkish patients. Genomic DNA obtained from 670 persons (339 patients with FMF and 331 healthy controls) was used in the study. Genotypes for an ACE gene I/D polymorphism and IL-4 gene 70 bp VNTR were determined by polymerase chain reaction with specific primers. To our knowledge, this is the first study examining ACE gene I/D polymorphism and IL-4 gene 70 bp VNTR polymorphism in FMF patients. As a result, there was a statistically significant difference between the groups with respect to genotype distribution (p<0.001). According to our results, ACE gene DD genotype was associated with an increased risk in FMF [p<0.001; OR (95%): 7.715 (4.503-13.22)]. When we examined ACE genotype frequencies according to the clinical characteristics, we found a statistically significant association between DD+ID genotype and fever (p=0.04). In addition IL-4 gene P1P1 genotype was associated with FMF (p<0.001). We propose that D allele or DD genotype of ACE gene and P1 allele or P1P1 genotype of IL-4 gene may be important molecular markers for susceptibility of FMF.

Angiotensin converting enzyme and methylenetetrahydrofolate reductase gene variations in fibromyalgia syndrome

OBJECTIVE Fibromyalgia syndrome (FM) is a common disease characterized by generalized body pain, sensitivity in certain physical areas (sensitive points), lowered pain threshold, sleep disorder, and fatigue. The study aimed to determine the effects ACE I/D and MTHFR C677T gene polymorphisms in Turkish patients with FM and evaluate if there was an association with clinical features. METHODS This study included 200 FM patients and 190 healthy controls recruited from the department of Physical Medicine and Rehabilitation at Gaziosmanpasa University in Tokat, Turkey. ACE I/D polymorphism genotypes were determined by using polymerase chain reaction (PCR) by specific primers. The MTHFR C677T mutation was analyzed by PCR-based restriction fragment length polymorphism (RFLP) methods. RESULTS We found a statistically significant relation between ACE polymorphism and FM (p<0.001, OR: 1.71, 95% CI: 1.28-2.27). However, this was not the case for ACE polymorphism and the clinical characteristics of the disease. There was also no statistically significant relation between MTHFR C677T mutation and FMS (p>0.05, OR: 1.20, 95% CI: 0.82-1.78), but dry eye and feeling of stiffness which are among the clinical characteristics of FMS were significantly related with MTHFR C677T mutation (p<0.05). CONCLUSION Our findings showed that there are associations of ACE I/D polymorphism with susceptibility of a person for development of fibromyalgia syndrome. Also, it is determined an association between MTHFR C677T polymorphism and feeling of stiffness and dry eye which are among the clinical characteristics of FM. Our study is the first report of ACE I/D and MTHFR C677T polymorphisms in fibromyalgia syndrome.

The Investigation of Obesity Susceptibility with IL-4 Gene Intron 3 VNTR and IL-6 Gene -597G/A Polymorphisms in a Turkish Population

Abstract Obesity results in a proinflammatory state starting within the metabolic cells as adipocyte, monocyte. The bioactive system, including cytokines as IL-4 and IL-6, contributes to the pathogenesis of conditions associated with obesity and favors inflammation. This study aimed to investigate the role of IL-4 gene intron 3 VNTR and IL-6 gene - 597G/A polymorphisms in the pathogenesis of obesity. The study included 127 patients with obesity (BMI>30kg/m2) and 110 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis for IL-4 gene and IL-6 gene polymorphisms. There was no statistical significant difference in the allele and genotype frequencies of both genes polymorphism in obesity patients and control groups (p>0.05). Additionally, there was no statistical significant difference in the combine genotype analysis of IL-4 gene intron 3 VNTR and IL-6 gene -597G/A polymorphism (p>0.05). These findings showed that there are not any associations of IL-4 gene intron 3 VNTR and IL-6 gene -597G/A polymorphisms with susceptibility of a person for development of obesity. This is the first report that investigates the relationships between susceptibility of obesity and IL- 4 gene intron 3 VNTR, IL-6 gene -597G/A polymorphisms.

Relationship between major depressive disorder and ACE gene I/D polymorphism in a Turkish population

Background Major depressive disorder (MDD) is a complex disease and a significant health problem that is prevalent across the world. Angiotensin-converting enzyme (ACE) has an important role in renin-angiotensin system (RAS) and converts inactive angiotensin I to a potent vasopressor and aldosterone-stimulating peptide angiotensin II. Levels of ACE in plasma vary according to the insertion/deletion (I/D) polymorphism of ACE gene. Objective The aim of the current study was to examine the influence ACE gene I/D variations on the risk of MDD. Methods In the present case-control study, we analyzed ACE I/D polymorphism in 346 MDD patients and 210 healthy subjects using polymerase chain reaction technique. Results Comparing the two groups, no significant difference was observed with regard to either genotype distributions or allele frequencies of the I/D polymorphism of ACE gene. Discussion Our findings suggest that the ACE I/D polymorphism is not associated with MDD in Turkish case-control study. Further studies are still needed.

Interleukin-1Ra rs2234663 and Interleukin-4 rs79071878 Polymorphisms in Familial Mediterranean Fever

OBJECTIVE Familial Mediterranean Fever (FMF) is an autosomal recessively inherited auto inflammatory disorder. MEFV gene, causing FMF, encodes pyrin that is associated with the interleukin-1 (IL-1) related inflammation cascade. The aim of this study was to investigate the relationship of interleukin-1 receptor antagonist (IL-1Ra) and interleukin-4 (IL-4) polymorphisms with the risk of FMF in the Turkish population. METHODS This study included 160 patients with FMF (74 men, 86 women) and 120 healthy controls (50 men, 70 women), respectively. Genotyping of IL-1Ra rs2234663 polymorphism was evaluated by gel electrophoresis after polymerase chain reaction (PCR). The IL-4 rs79071878 polymorphism was determined by PCR-based restriction fragment length polymorphism (PCR-RFLP) analysis. The results of analyses were evaluated for statistical significance. RESULTS There was no significant difference in IL-1Ra genotype and allele distributions between FMF and the control groups (p>0.05). However, a significant association was observed between FMF patients and control groups according to IL-4 genotype distribution (p=0.016), but no association was found in the allelic frequency of IL-4 between FMF patients and the controls (p>0.05, OR: 1.131, CI 95%: 0.71-1.81). CONCLUSIONS The IL-4 rs79071878 polymorphism, was associated whereas the IL-1Ra rs2234663 polymorphism was not associated with FMF risk in the Turkish population. Larger studies with different ethnicities are needed to determine the impact of IL-1Ra and IL-4 polymorphism on the risk of developing FMF.

Effects of subtelomeric copy number variations in miscarriages.

Abstract Purpose: This study was performed on miscarriage samples for chromosome analysis to detect copy number variations (CNVs) related to subtelomeric regions, and with these results we aimed to adapt multiplex ligation-dependent probe amplification (MLPA) method for prenatal diagnosis. Materials and methods: The cell cultures and DNA isolations were performed on 60 miscarriage samples. For maternal contamination analysis, DNA isolations and quantitative fluorescent polymerase chain reactions were done using peripheric blood of mothers who had miscarriages. We compared short tandem repeat peak profiles of miscarriage samples and mothers. The subtelomeric regions of the chromosomes were assessed using the MLPA method. Results: Of 43 miscarriage samples, 19 had normal karyotype (44.2%), 10 had numerical abnormalities (23.3%), and 2 had structural abnormalities (4.7%). Subtelomeric 16q duplication was determined in 2 of the 30 miscarriage samples investigated with MLPA method (6.6%). Conclusion: There is no statistically significant difference between two groups (p > 0.05). However, the fact that the 6.6% subtelomeric CNV found in miscarriage samples was not found in controls, showed that further studies are required. We recommend that the miscarriage samples of the couples with recurrent miscarriage should be analyzed in terms of subtelomeric CNV after the exclusion of other clinical reasons. Chinese abstract 目的：通过对流产物取样进行染色体分析来检测端粒近端区域基因拷贝数异变（CNVs）情况，旨在将多重连接探针扩增技术（MLPA）用于产前诊断。 材料与方法：对60例流产物样本进行细胞培养和DNA分离。采用母体外周血进行母体细胞污染分析、DNA分离及荧光定量聚合酶链反应。我们比较了流产样本和母血中短串联重复序列峰值情况。采用MLPA对染色体亚端粒区进行评估。 结果：43例流产样本中，19例核型正常（44.2%）。10例染色体数目异常（23.3%）2例结构异常（4.7%）。采用MLPA对30例流产样本进行检测，其中2例发生端粒区域16号染色体长臂复制（6.6%）。 结论：两组没有明显的统计学差异（p>0.05）。然而流产样本中发现6.6%端粒近端区域基因拷贝数异变，而控制组中没有发现，尚需进一步研究。我们建议对于存在复发性流产的夫妇在排除其他临床原因外应对流产物样本进行端粒近端区域基因拷贝数异变分析。