Genetic analysis of C5a receptors in neutrophils from patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autoinflammatory disease, characterized by MEFV gene mutations and self-limited recurrent episodes of fever and localized serositis. Complement system is a key regulator of the inflammatory process. The aim of this study was to investigate the genetic alterations and mRNA expression pattern of C5aR and C5L2 genes in neutrophils from attack-free FMF patients. No mutations were observed in the two receptors’ genes, while the genetic alteration observed in the C5aR1 gene was identified as N279 K polymorphic variant. Furthermore, lower mRNA expression of C5L2 gene was observed in neutrophils from FMF patients compared to control subjects. The binding capacity of rhC5a and the ability to produce reactive oxygen species was similar in neutrophils from healthy subjects and FMF patients and independent of the presence of N279 K polymorphism or mRNA expression of C5L2.     

Analysis of common MDR1 (ABCB1) gene C1236T and C3435T polymorphisms in Turkish patients with familial Mediterranean fever

The multidrug resistance (MDR1) gene encodes a P-glycoprotein that plays a key role in drug bioavailability and response to drugs in different human populations. More than 50 SNPs have been described for the MDR1 gene. Familial Mediterranean fever (FMF) is considered an autosomal recessive hereditary disease, associated with a single gene named the Mediterranean fever gene (MEFV). However, about one-third of FMF patients have only one mutated allele, suggesting that this disease is expressed as an autosomal dominant trait with partial penetration or an additional gene might be responsible for the disease. We made genotype and haplotype analyses of the MDR1 gene in 142 FMF patients and 130 unrelated Turkish subjects; two MDR-1 genetic markers (C1236T and C3435T) were analyzed by PCR-RFLP analysis. FMF patients had a significantly higher frequency of the 3435 CT genotype compared with the control group (59.9% in FMF patients versus 44.6% in controls; odds ratio [OR] = 1.85; 95% confidence interval [CI] = 1.14-3.00). Based on haplotype analysis, the T-C shift was significantly more frequent in controls (14.4% versus 7.1% in FMF patients). This haplotype could be protective for FMF disease (OR = 0.45; 95%CI = 0.25-0.84). The frequency of CC-CT (1236-3435) binary genotype was significantly higher in FMF patients (14.79% versus 4.61% in controls; OR = 3.59; 95%CI = 1.40-9.20).     

Significance of MEFV gene R202Q polymorphism in Turkish familial Mediterranean fever patients

Objective

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever and inflammation in the peritoneum, synovium, or pleura, accompanied by pain. The disease is associated with mutations in the Mediterranean fever (MEFV) gene, which encodes for the pyrin protein. The aim of this study was to explore the frequency and clinical significance of the R202Q (c.605G>A) polymorphism in exon 2 of the MEFV gene in a cohort of Turkish patients with FMF.

Methods

The study included 191 patients with FMF and 150 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MEFV gene R202Qpolymorphism.

Results

The genotype and allele frequencies of R202Q polymorphism showed a statistically significant difference between FMF patients and controls (p < 0.0001 and p = 0.0004, respectively) and especially the homozygous AA genotype was significantly higher in FMF patients than healthy controls (p = 0.0002; odds ratio = 6.27; 95% CI = 2.1–18.3). However no significant association was observed between clinical and demographic features of FMF patients and R202Qpolymorphism.

Conclusion

The results of this study showed that there was a high association between MEFV gene R202Q polymorphism and FMF. R202Q polymorphism should be included in routine molecular diagnosis of FMF patients.     

The LOX-1 3′UTR188CT polymorphism and coronary artery disease in Turkish patients

In coronary artery disease (CAD), a potentially reversible factor leading to cardiac death is left ventricular hypertrophy (LVH). The 3′untranslated region (3′UTR) 188CT polymorphism of lectin-like oxidized low-density lipoproteins receptor-1 (LOX-1) gene has been associated with an increased risk for CAD. We aim to investigate, in a Turkish population, whether 3′UTR188CT variation could affect the development of LVH in CAD patients. In a population-based case–control study, we compared 83 cases with CAD and 99 healthy controls for this polymorphism. The LOX-1 3′UTR188CT genotypes were determined by PCR–RFLP technique. LOX-1 3′UTR188 TT genotype was associated with significantly increased systolic blood pressure (P = 0.047) and risk of LVH (P = 0.014, OR: 3.541) when compared with the C allele carriers. In addition, the TT genotype was positively associated with decreased levels of HDL-cholesterol in the control subjects (P = 0.031) and increased levels of VLDL-C in the patient group (P = 0.009). The LOX-1 3′UTR188CT gene polymorphism may predispose to the development of LVH in CAD patients, dependent on blood pressure.     

No association between methylenetetrahydrofolate reductase C677T polymorphism and breast cancer

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme (EC 1.5.1.20), that reduces 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a carbon donor for the homocysteine to methionine conversion. MTHFR is a key enzyme that regulates folate metabolism which has an important role in DNA synthesis, DNA repair and methylation. The association between MTHFR C677T polymorphism and breast cancer has been investigated in several previous studies. Some researchers have shown an association between C677T polymorphism and breast cancer, but not all researchers found this association however. This study was designed to investigate, in the Turkish population, the association of MTHFR C677T polymorphism and breast cancer. Forty women patients with breast cancer and 68 healthy women were included in the study. MTHFR gene polymorphism was determined by the PCR-RFLP method. SPSS 10.0 for windows was used to determine statistical significance. No differences were observed in the distribution of MTHFR genotypes or allele frequencies in the cases versus the controls. It was found that the frequencies of MTHFR polymorphism were 55%, 40%, 5% for CC, CT, TT genotype in patients and 56%, 38%, 6% in healthy controls respectively. Furthermore, association was observed among family history, metastatic risk and MTHFR genotypes in patients. Our data fail to support a relationship between MTHFR C677T and the risk for breast cancer. It may be that there are ethnic differences in terms of this relationship.     

Methylene tetrahydrofolate reductase C677T mutation and left ventricular hypertrophy in Turkish patients with type II diabetes mellitus

This study was designed to investigate, in the Turkish population, the association of methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism and left ventricular hypertrophy (LVH) in patients with type II diabetes mellitus. Our study included 249 patients with type II diabetes mellitus (102 men, 147 women) and 214 healthy volunteers as controls (91 men, 123 women). MTHFR C677T genotypes were determined by polymerase chain reaction, restriction fragment length polymorphism techniques. No differences were observed in the distribution of MTHFR genotypes or allele frequencies in the cases versus the controls. The frequency of the MTHFR-mutated allele (T) was 31.7% in the type II diabetes mellitus versus 31.1% of the controls. The homozygous mutation (T/T) in the MTHFR gene was identified in 12% of the type II diabetes mellitus versus 9.3% of the controls. Patients with the TT genotype showed a higher prevalence of LVH when compared to patients with the CC and CT genotypes (p = 0.01). The MTHFR gene C677T mutation may be a possible risk factor for the development of LVH in the type II diabetic patients.     

Association of angiotensin converting enzyme (ACE) gene I/D polymorphism and rheumatoid arthritis

We sought to determine the frequency of I/D polymorphism genotypes of angiotensin converting enzyme gene in Turkish patients with rheumatoid arthritis. Genomic DNA obtained from 256 individuals (110 patients with rheumatoid arthritis and 146 healthy controls) was used in the study. ACE gene I/D polymorphism genotypes were determined using polymerase chain reaction using I and D allele-specific primers. There was a statistically significant difference between the groups with respect to genotype distribution (p = 0.001). A significant difference was found in frequencies of ACE I/D alleles between patients and controls, with RA patients having a higher representation of D and lower representation of I alleles compared to controls (p < 0.001). As a result of our study, angiotensin converting enzyme gene I/D polymorphism DD genotype could be a genetic marker in rheumatoid arthritis in the Turkish study population.     

Frequency of angiotensin II type 1 receptor gene polymorphism in Turkish acute stroke patients

This study was performed in acute stroke patients in the Turkish population to determine the frequency of the A1166C polymorphism in the AT1 gene and to examine the role of this polymorphism in acute stroke development. In this study, 257 genomic DNA samples were analysed (from 206 acute stroke patients and 51 healthy individuals). Genomic DNA was prepared from peripheral blood using the salt‐extraction method. The presence of the A1166C polymorphism in the AT1 gene was determined using the polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) method. PCR products were separated by 2% agarose gel electrophoresis and visualized by a charge‐coupled device (CCD) camera. In this study, the allele frequency at the A1166C position was 92% A and 8% C for control and 97% A and 3% C for patients. This difference in allele frequency between the control group and the patient group was not statistically significant. However, genotype and allele frequencies showed a significant difference (P < 0.001) in the control and the patient groups. The results of this study show no relationship between the A1166C polymorphism in the AT1 gene and acute stroke in the Turkish population.     

DD genotype of ace gene I/D polymorphism is associated in a turkish study population with osteoarthritis

This study was conducted in Turkish osteoarthritis patients to determine the frequency of I/D polymorphism genotypes of angiotensin converting enzyme gene, and to examine the role of this polymorphism in osteoarthritis development. Genomic DNA obtained from 200 persons (135 patients with osteoarthritis and 65 healthy controls) was used in the study. DNA was multiplied by polymerase chain reaction using I and D allele-specific primers. Polymerase chain reaction products were assessed with CCD camera by being exposed to 2% agarose gel electrophoresis. There was statistically significant difference between the groups with respect to genotype distribution (P < 0.001). The D allele frequency was indicated as 69% and I allele was as 31% in the patients, whereas it was 55–45% in the control group. Consequently, in this study, we may assert that ACE gene I/D polymorphism DD genotype determination is significant criteria for identifying patients who are likely to develop osteoarthritis in east population of Turkey.     

Genotype and allele frequency of human multidrug resistance (MDR1) gene C3435T polymorphism in Denizli province of Turkey

Human p-glycoprotein encoded by human multidrug resistance (MDR1) gene, is a transmembrane protein that serves as efflux pump for a wide variety of lipophilic compounds possessing a physiological role in protecting cells against the DNA damaging of certain xenobiotics. According to the published data, the frequency of C3435T polymorphism differs depending on the different ethnical populations such as Asian, African, and Caucasians populations. In our study, we identified the MDR1 C3435T polymorphism in 150 healthy volunteers in Denizli province of Turkey. DNA was extracted from peripheral blood samples by standard phenol/chloroform extraction method. Polymerase chain reaction–restriction fragment length polymorphism was used for the detection of C3435T single nucleotide polymorphism. We obtained CC, CT and TT genotype frequencies as 20, 53 and 27%, respectively. According to our results, the C allele in Turkish population (Denizli province, west of Turkey) is found 47% and this data shows similarity with Caucasian (UK and German) populations and significantly lower than African populations (p < 0.001). Our study is the first data on the genotype and allele frequency of the human multidrug resistance (MDR1) Gene C3435T Polymorphism in Denizli Province at regional basis in Turkey. Our results could serve as a basis for large-scale correlation studies on the relevance of C3435T genotype in cancer therapy and other diseases in Turkish population. Investigation of genotype frequencies related with p-glycoprotein substrates should be investigated in large scale at regional bases in Turkish population. The scaled-up data might help either to the use of p-glycoprotein substrates to be used for therapeutic applications and population genetics considering the genotype frequencies possibly occurring throughout the history in Anatolian basin.     

G-protein β3 subunit gene C825T polymorphism in patients with vesico-ureteric reflux

The C825T polymorphism in the GNB3 gene encoding a β3 subunit from heterotrimeric G-proteins correlates strongly with the variation in activity of the G-proteins. It has so far been associated with a variety of medical conditions, but has not been tested for association with vesico-ureteric reflux (VUR). Primary VUR is a condition of genetic origin that appears to be inherited in an autosomal dominant mode, but with reduced penetrance. The constitutional change in G-protein-mediated cell signaling associated with the C825T polymorphism might be one of the factors that participate in the development of VUR by modifying the effect of still unknown mutated gene(s). A significant difference in genotype frequencies (χ² = 7.38, P = 0.025, df = 2) was observed between patients with primary VUR (33 CC homozygotes, 40 CT heterozygotes, 12 TT homozygotes) and healthy controls with no medical record of reflux (114 CC homozygotes, 88 CT heterozygotes, 18 TT homozygotes). This result suggests that the C825T polymorphism of the GNB3 gene might be associated with the development of VUR.     

Effect of G(-174)C polymorphism in interleukin-6 gene on cardiovascular disease in type 2 diabetes patients

Interleukin-6 (IL-6) is an important pro-inflammatory cytokine of relevance to cardiovascular diseases. The aim of this case-control study was to evaluate the association between the G(-174)C functional polymorphism in the IL-6 gene and risk of cardiovascular disease (CVD) in type 2 diabetes patients. We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the G(-174)C polymorphism by polymerase chain reaction (PCR) and restriction analysis. There were no significant differences in the distribution of genotypes and alleles between T2DM patients and healthy controls. Significantly higher C allele frequency was observed in CVD+ patients compared to CVD- subgroup (53% vs. 32%, p < 0.0001). The odds ratio for C allele was 2.4 (95% CI 1.99–2.9, p < 0.0001) and for CC genotype 4.55 (95% CI 3.12–6.63, p < 0.000). When the distribution of G(-174)C polymorphism was compared in subgroups with different clinical phenotypes of CVD, a significant association of CC genotype with myocardial infarction was observed. Forty eight percent of patients with MI had the CC genotype compared to 22% of patients without MI (p < 0.0001). In conclusion, type 2 diabetes patients carrying the C allele of the IL-6 G(-174)C polymorphism have a significantly increased risk of CVD.     

Association of serotonin 2A receptor and lack of association of CYP1A2 gene polymorphism with tardive dyskinesia in a Turkish population

The aim of this study was to investigate the possible association of serotonin 2A receptor gene (HTR2A) -1438 G/A polymorphism and CYP1A2 gene 163C/A polymorphism with tardive dyskinesia (TD) in a Turkish population. A total of 47 patients with persistent TD, 80 patients who were consistently without TD, and 100 healthy controls were included in this study. The polymorphic regions of -1438 G/A polymorphism of HTR2A receptor gene (rs6311) and 163C/A of CYP1A2 (rs762551) gene were amplified using polymerase chain reaction (PCR), followed by digestion with restriction enzymes MspI and Bsp1201. Genotype and allele frequencies were calculated by the chi(2)-test. Crude and adjusted odds ratios (ORs) were estimated, and 95% confidence intervals (CIs) were computed by multivariate logistic regression analysis. The genotype and allele frequencies of HTR2A and CYP1A2 gene were similar in schizophrenia with TD, schizophrenia without TD, and healthy controls. The logistic regression analysis showed that cumulative exposure to antipsychotic drugs for every year (p = 0.003; OR = 1.15; CI = 1.07-1.23), and AA genotype of HTR2A gene (p = 0.0258; OR = 4.34; CI = 1.19-15.81) are risk factors for TD. The same logistic regression model showed no association between CYP1A2 polymorphism and TD. The results of the present study seem to indicate that HTR2A gene polymorphism influences the tendency to express TD following prolonged antipsychotic drug exposure in Turkish schizophrenia patients.     

Effects of the PPARG P12A and C161T gene variants on serum lipids in coronary heart disease patients with and without Type 2 diabetes

We investigated whether PPAR-γ2 gene polymorphisms are associated with serum lipids and the occurrence of coronary heart disease (CHD) prospectively characterised for the presence or absence of Type 2 diabetes in a Turkish population. Our study included 202 patients with CHD (102 with diabetes, 100 without diabetes) and 105 controls. PPARγ genotypes were determined by PCR-RFLP technique. The PPARγ-C161T CC homozygote genotype was associated with significantly increased CHD risk when compared with the T allele carriers (CT+TT) in CHD patients with diabetes (OR:1.951, 95%CI: 1.115-3.415, P = 0.019), whereas PPARγ-P12A polymorphism was not associated with CHD risk (P > 0.05). Serum HDL-C levels were significantly lower in controls with the P12A heterozygote when compared with the P12P homozygote (P = 0.002). In the CHD patients with diabetes, CT heterozygote genotype showed higher serum triglyceride than the CC homozygote genotype (CT:2.42 ± 1.89 vs. CC:1.61 ± 0.21, P = 0.015). Our findings shows the association of these two polymorphisms with serum triglyceride levels, which was increased in the order of P12P-CC < P12P-CT < P12A-CC < P12A-CT in the CHD patients with diabetes. Furthermore, we observed that the increasing effects of the CT genotype on serum triglyceride levels could be modified by PPARγ P12A polymorphism (P12A-CT:2.30 ± 1.75 vs. P12P-CC:1.79 ± 1.14, P = 0.028). We suggested that homozygote CC genotype of the PPARγ C161T polymorphism might be associated with an increased CHD risk especially in patients with diabetes. We observed that the C161T CT heterozygote genotype shows an unfavorable effect on serum lipid profile in CHD patients with diabetes and this effect was weaken with the presence of P12P homozygote genotype.     

CCR5-Delta32 Allele is Associated with the Risk of Developing Multiple Sclerosis in the Iranian Population

The 32-base pair deletion on the C–C chemokine receptor 5 gene (CCR5-delta32) is known as a protective allele against immune system disorders. We have studied this variation in Iranian multiple sclerosis (MS) patients and healthy controls. DNA samples were prepared from the whole blood of 254 patients with MS and 380 healthy controls. We amplified the fragment including the CCR5-delta32 polymorphism and visualized the products in a documentation system after agarose gel electrophoresis. Data were analysed using one-way ANOVA and Fisher’s exact tests with SPSS-v13 and STATA-v8 software. The delta32 allele was more frequent in MS patients when compared with controls (OR = 2.3, P < 0.0001). Also, we found a significant difference in the frequency of the delta32/delta32 genotype among patients and controls (OR = 7.4, P < 0.001). The mean age at onset and progression index was not significantly different between patients with various genotypes. According to our study, the delta32 allele of the CCR5 gene might be a predisposing factor for MS development in the Iranian population. However, there were no associations between this polymorphism and the clinical course of the disease in this study.     

Association of MDR1 C3435T polymorphism with bipolar disorder in patients treated with valproic acid

P-glycoprotein (P-gp), an efflux transporter protein, is an ABC transporter encoded by the multidrug resistance 1 gene (MDR1, ABCB1). The common synonymous C3435T polymorphism in exon 26 is reported to associate with lower P-gp functional expression and drug uptake. Many extended pharmacogenomics, functional, and complex disease association studies focused mainly on this polymorphism. We investigated the association of exon 26 C3435T genetic variants of MDR1 gene with susceptibility to bipolar disorder and serum valproic acid concentration. Totally, 104 patients meeting DSM-IV criteria for bipolar disorder and 169 controls were admitted to the study. There was statistically significant difference between the genotypes of bipolar patients (CT 91.2%, TT 6.8%, and CC 2%) and controls (CT 52.7%, TT 26%, CC 21.3%) although their allelic distribution was similar. The serum valproic acid concentrations of the patients with CT, TT and CC genotypes were 72.92 ± 20.55, 80.47 ± 14.01 and 68.29 ± 12.17 μg/ml, respectively, and there was no significant difference between the C3435T genotypes.     

Association of the colorectal cancer and <Emphasis Type="Italic">MDR1</Emphasis> gene polymorphism in an Iranian population

The human multidrug resistance (MDR1) gene product P-glycoprotein is highly expressed in intestinal epithelial cells, where it constitutes a barrier against xenobiotics, bacterial toxins, drugs and other biologically active compounds, possibly carcinogens. In this study, an association of MDR1 gene polymorphism and the occurrence of colorectal cancer were evaluated. In this case-control-designed 118 unrelated colorectal cancer and 137 sex-and-ages matched healthy controls were enrolled. The C3435T MDR1 gene polymorphism was identified using the polymerase chain reaction-restriction fragment length polymorphism method. Significantly increased frequencies of the 3435T allele and the 3435TT were observed in patients with colorectal cancer compared with controls (P = 0.03; OR, 95% CI; 1.46 for 3435T allele and P = 0.003; OR, 95% CI; 2.2 for 3435TT genotype). In contrast, frequency of genotype TT was significantly higher in controls compared to colorectal cancer (P = 0.006; OR, 95% CI; 0.49 for TC genotype). In this study suggest that C3435T MDR1 polymorphism has an association with colorectal cancer. The results support that the presence of allele C results in decreased susceptibility to colorectal cancer.     

Lack of association between catalase gene polymorphism (T/C exon 9) and susceptibility to vitiligo in a Turkish population

Accumulation of hydrogen peroxide (H(2)O(2)) and low catalase (CAT) activity have been demonstrated in the epidermis of vitiligo patients. We investigated a possible association between the CAT exon 9 (Asp-389) gene and vitiligo susceptibility in the Turkish population. Thirty-four patients with vitiligo and 49 gender, age and ethnic matched controls were enrolled in the study. Genotyping was done by PCR-RFLP. The CAT exon 9 (Asp-389) genotype and allele frequencies of vitiligo patients did not differ significantly from those of healthy controls. We found no association between CAT (Asp-389) gene polymorphism and vitiligo susceptibility in Turkish vitiligo patients.     

Monocyte chemoattractant protein-1 (MCP-1) gene polymorphism as a potential risk factor for cardiovascular disease in hemodialyzed patients

Aim: Polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene (A-2518G) has been associated with functional effects. The aim of the present study was to assess the effect of this polymorphism on end-stage renal disease (ESRD) and cardiovascular disease (CVD) in hemodialyzed patients. Methods: A total of 720 patients with ESRD treated with hemodialysis (450 patients with CVD) and 325 healthy control subjects were genotyped for the MCP-1 -2518 polymorphism by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) procedure. Results: There was a significant difference in genotype frequencies between entire group of hemodialyzed patients and controls (p < 0.01). The odds ratio for the risk allele was 1.85, 95% CI 1.49–2.32 (p < 0.01). Hemodialyzed patients were divided into subgroups with CVD (n = 450) and without CVD (n = 270). The G allele carriers occurred with significantly higher frequency in patients with CVD (62% vs. 38% in patients without CVD and 36% in controls). The odds ratio for the risk allele for patients with CVD vs. those without CVD was 2.17, 95% CI 1.71–2.79. There was no statistically significant difference in the distribution of MCP-1 genotypes between ESRD patients without CVD and healthy controls. Conclusion: Our results demonstrate for the first time an association between the polymorphism in the regulatory region of the MCP-1 gene and susceptibility to CVD in hemodialyzed patients.     

Methylenetetrahydrofolate reductase C677T mutation in patients with alopecia areata in Turkish population

Objective

Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme regulating folate metabolism and it is thought to influence DNA methylation and nucleic acid synthesis. Mutations in the MTHFR gene have been associated with several autoimmune disorders in previous studies. Alopecia areata (AA) is considered to be a tissue-specific autoimmune disease as the hair follicle has been targeted and antibodies to their own hair follicle structures have been developed. Since there is a common shared pathway between AA and other autoimmune disorders, we aimed to investigate a possible association between the MTHFR gene C677T mutation and AA susceptibility in the Turkish population.

Methods

The study included 136 patients affected by AA and 130 healthy controls. Genomic DNA was isolated and genotyped using a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MTHFR gene C677T mutation.

Results

The distributions of genotype and allele frequencies of MTHFR gene C677T mutation were statistically different between AA patients and the control group (p = 0.036 and p = 0.011, respectively). High differences were also observed when the patients and controls were compared according to CC versus CT + TT (p = 0.012). CT + TT genotypes and T allele of MTHFR gene C677T mutation were found to be a susceptibility factor for AA in the Turkish population.

Conclusion

The results suggest that MTHFR gene C677T mutation may have an effect on the risk of alopecia areata in the Turkish population. This is the first study reporting the association between the MTHFR (C677T) genotype and AA.