Associations of IL-17 and IL-17 receptor polymorphisms with Behçet's disease in Denizli Province of Turkey.

Although the etiopathogenesis of Behçet's disease is not known, studies conducted in different populations show that it is a multifactorial disease that is thought to develop as a result of the interaction of environmental and genetic factors. IL-17 is thought to induce the neutrophilic inflammation and the tissue damage mediated by immune response in patients. Polymorphisms in the gene region encoding IL-17 and IL-17R molecules may play a critical role in the pathogenesis of the disease and contribute to the elucidation of disease mechanism. We aimed to show the association of IL-17A, IL-17F, and IL-17RC polymorphisms and haplotypes in Behçet's disease patients and its clinical features. We genotyped IL-17A (rs4711998 (A/G), rs8193036 (C/T), rs2275913 (A/G), rs3819025 (A/G), rs8193038 (A/G), rs3804513 (A/T), rs1974226 (C/T), rs3748067 (C/T)); IL-17F (rs763780 (T/C), rs2397084 (T/C)); and IL-17R (IL-17RC) (rs708567 (C/T)) polymorphisms in 88 patients with Behçet's disease and 133 healthy controls using PCR-RFLP-based approach. The results of our study showed that polymorphisms of IL-17A, rs8193036 (C/T), rs3819025 (G/A), rs3804513 (A/T), IL-17F rs2397084 (T/C), and IL-17RC rs708567 (C/T) are associated with the susceptibility to the BD. When the haplotype distributions of all loci of IL-17Aand IL-17A/IL-17F together were examined and in contrast to the data obtained from the controls, the GTGGAACC (27.84%) and GTGGAACCTT (25.57%) have the highest frequencies. In conclusion, the allele and genotype frequency differences of the IL-17A, IL-17F, and IL-17R and haplotype frequencies between Behçet's disease and controls indicate that the genetic structure of Behçet's disease may be different.

The role of UGT1A1 promoter polymorphism and exon-1 mutations in neonatal jaundice.

OBJECTIVE: In the present study, we investigated the effects of promoter polymorphism and an exon-1 mutation (G71R) in the UGT1A1 gene in neonates with unexplained hyperbilirubinemia and direct Coombs-negative [DC(-)] ABO incompatibility. METHODS: Two-hundred term neonates in their first week of life and without additional icterogenic factors were included in the study. Neonates with a serum total bilirubin (STB) level ≥17 mg/dL constituted the hyperbilirubinemia group (n = 100), while the control group comprised healthy neonates with a STB level <12.9 mg/dL (n = 100). The cases were further subdivided into unexplained hyperbilirubinemia (n = 50), ABO(+) hyperbilirubinemia (n = 50), ABO(-) control (n = 50), and ABO(+) control (n = 50) groups on the basis of the presence or absence of DC(-) ABO incompatibility. DNA was isolated from peripheral blood and amplified by PCR, and UGT1A1 gene promoter and exon-1 were sequenced to verify sequence alterations. RESULTS: The frequency of TA6/6, TA6/7, TA7/7, and GGA/GGA, GGA/AGA, AGA/AGA genotypes was found to be 63.5%, 21%, 15.5%, and 91.5%, 8%, 0.5%, respectively. While both heterozygous and homozygous TA7 polymorphism increased risk of hyperbilirubinemia in the ABO(+) hyperbilirubinemia group (heterozygous OR 16.76, 95% CI:3.52-79.70, p < 0.0001; homozygous OR 6.81, 95% CI:1.98-23:42, p = 0.002), only heterozygous TA7 polymorphism increased jaundice risk (OR 5.08 95% CI:76-14.65, p = 0.003) in unexplained hyperbilirubinemia. But, the coexistence of G71R mutation and promoter polymorphism or G71R mutation and DC(-) ABO incompatibility did not increase the severity of hyperbilirubinemia (p > 0.05). CONCLUSIONS: UGT1A1 gene promoter polymorphism and G71R mutation are possible risk factors for Turkish neonates with DC(-) ABO incompatibility and unexplained hyperbilirubinemia.

The IL-8 Gene Polymorphisms in Behçet's Disease Observed in Denizli Province of Turkey.

Behçet's disease is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration and uveitis with unknown pathogenesis. IL-8, a proinflammatory cytokine, has been found increased in the active stage of BD. DNA samples were obtained from 88 patients with BD and 112 healthy control subjects in Denizli province of Turkey. All genotyping experiments of SNPs in IL-8 gene were performed using polymerase chain reaction-restriction fragment polymorphism. We found that IL-8 -845 T > C and -738 T > A sites are non-polymorphic. There were no differences in the polymorphisms of IL-8 +396 G/T, +781 C/T, and +1633 C/T sites except IL-8 -251 T > A in between patients and healthy controls. Analysis of IL-8 polymorphisms indicates that the distribution of frequencies seems to be associated with -251 T > A and gender, -251 T > A and erythema nodosum, -251 T > A and ocular involvement, +781 C > T and erythema nodosum, +396 G > T and pathergy positivity, and +1633 C > T and papulopustular lesion. We demonstrated that the frequencies of IL-8 haplotypes were significantly different with BD patients than control group. We found that the distribution of IL-8 haplotypes was significantly different with genital ulcers, ocular involvement, positive pathergy test, erythema nodosum, papulopustular lesions, and arthritis with BD patients than healthy control individuals. Our study suggests that IL-8 gene polymorphisms may affect susceptibility to BD and increase the risk of developing disease. In order to confirm and assess the association of IL-8 and other cytokine gene polymorphisms in the pathophysiology of BD, large cohort studies are needed.

Association of a genetic polymorphism of the alcohol-metabolizing enzyme ADH1C with alcohol dependence: results of a case-control study.

OBJECTIVE: Alcohol dependence causes serious problems which may be influenced by genetic factors associated with alcohol metabolism. The aim was to investigate the allelic and genotypic difference in distribution of a polymorphism in alcohol dehydrogenase 1C gene (ADH1C) between alcohol-dependent individuals and controls, and to examine if these genotypes were associated with the age at which the patient became alcohol-dependent. METHODS: We conducted a case-control study including 90 alcohol-dependent cases and 100 historic controls. The genomic DNA was isolated and the alleles were analyzed with an RFLP. RESULTS: The ADH1C*1 allele frequencies were 0.89 (95% CI 0.84-0.91) in controls and 0.68 (95% CI 0.61-0.74) in alcohol-dependent patients. The frequencies of the ADH1C*2 allele were 0.11 (95% CI 0.07-0.14) and 0.32 (95% CI 0.25-0.38) among controls and alcohol-dependent patients, respectively (p < 0.0001). The ADH1C*1/*1 genotype frequency was significantly higher in the control group (77%) compared to that of the alcohol-dependents (51%, p < 0.0001). The ADH1C*1/*2 genotype frequency was significantly lower in the control group (23%) compared to that of the alcohol-dependents (42%, p < 0.0001). We obtained no statistically significant difference among the ADH1C genotype groups regarding age. CONCLUSIONS: These findings suggest that a significantly higher presence of ADH1C*2 allele is associated with alcohol dependence in a Turkish population. Studies with other related polymorphisms are needed to more precisely estimate the association of alcohol dependence with ADH1C.

Allele frequency of VNTR locus D1S80 observed in Denizli Province of Turkey.

The variable numbers of tandem repeats (VNTR) locus D1S80, located on chromosome 1 (1p35-36), has a repeat unit 16 bp in length, and different numbers of these repeat units have been observed for populations of different origins and ethnicity. We used a molecular identification method based on capillary electrophoresis separation to analyze D1S80 locus polymorphism among 74 subjects from Denizli province, Turkey, finding an amplified fragment length size of 379-635 bp. Allele repeat numbers were deduced from these sizes and sequence comparison. The most common alleles were repeat units 24 (34.3%) and 18 (22.4%), with frequencies of 0.414 and 0.207, respectively. Other alleles were 25 (7.86%), 28 (5.71%), 22 (4.25%), and 29 (2.86%). The allele with 23 repeat units was not observed. Results were in Hardy-Weinberg linkage disequilibrium. Observed heterozygosity was 0.614, and expected heterozygosity was 0.787. Theta(k) value was 4.86 (95% confidence interval limits). Capillary electrophoresis is a powerful approach for accurate identification of VNTR loci, especially for low base pair units like D1S80, for prenatal diagnosis, linkage analysis, forensic identification, paternity testing, anthropological research, and phylogenetic studies.

Hb D-Los Angeles [beta121(GH4)Glu>Gln] and Hb Beograd [beta121(GH4)Glu>Val]: Implications for their laboratory diagnosis and genetic origins.

OBJECTIVE: The aim of this study was to determine the laboratory diagnosis and genetic origins of the hemoglobin (Hb) variants, Hb D-Los Angeles and Hb Beograd observed frequently in our region. MATERIAL AND METHODS: Hb variants were investigated in one Hb D-Los Angeles and two Hb Beograd families. These families were unrelated with each other. For the determination of Hb variants, alkaline/acid electrophoresis, HPLC, DE-52 micro-column chromatography procedures were applied. Mutations were determined by non-radioactive fluorescence automated DNA sequencing. Beta globin gene cluster haplotypes were identified by RFLP analysis at seven loci known as ε-Hinc II, Gγ-Hind III, AΨß-Hind III, 5'Ψß-Hinc II, 3'Ψß-Hinc II, ß-Ava II ve 3'ß-Hinf I. RESULTS: Three novel beta globin gene cluster haplotypes were identified as in relation with Hb D-Los Angeles [--+-+++], Hb Beograd [+----++ and -+-(+/-)(+/-)+(+/-)]. These haplotypes were reported for the first time in the world population Conclusion: In this study we emphasize the importance of DNA seqeuncing and other laboratory procedures for the identification of Hb variants in premarital diagnosis. On the other hand we discuss also the genetic origins of these Hb variants.

Beta globin gene cluster haplotypes of the beta thalassemia mutations observed in Denizli province of Turkey.

OBJECTIVE: Our aim is to identify the beta globin gene cluster haplotypes for the beta thalassemia mutations in Turkey at regional basis. Beta thalassemia mutations included in this study were IVS-I-110 (G>A), FSC 8/9 (+G), IVS-II-1 (G>A), IVS-I-5 (G>C), IVS-I-1 (G>A), IVS-I-6 (T>C) and FSC 8 (-AA). METHODS: We studied 22 unrelated patients with ß-thalassemia major and 72 unrelated healthy subjects from our Department's DNA bank. Haplotype analysis was done by polymerase chain reaction (PCR)-based restriction enzyme digestion for the beta globin gene cluster of the following polymorphic restriction sites: Hinc II 5' to ε, Hind III 5' to Gγ, Hind III in the IVS-II 5' to Aγ, Hinc II in pseudo ß, Hinc II 3' to pseudo ß, Ava II in ß, Hinf I 3' to ß. Associated haplotypes for the normal control samples (72 individuals, 144 chromosomes) were determined by Arlequin 3.1 software with unknown gametic phase. RESULTS: According to the results obtained, the most frequent beta globin gene cluster haplotypes in the normal population are (+----++), (+----+-), (-+-++++), (+-----+) with the frequencies of 28.6 %, 17.2 %, 9.8 % and 8.3 % respectively. IVS-I-110 mutation is linked with the haplotypes (+----++) and (+-----+). Observed haplotypes are (+----++) for FSC 8/9 (+G), (-+-+++-) for IVS-II-1 (G>A), (-+-++-+ and -+-++++) for IVS-I-5 (G>C), (+----+- and +------) for IVS-I-1 (G>A), (-++---+) for IVS-I-6 (T>C) and (+-----+) for FSC 8 (-AA). CONCLUSION: In conclusion, our region shows the Mediterranean character for the beta thalassemia mutations. According to the obtained results, IVS-I-110 (G>A) mutation linked with haplotype VII (+-----+), IVS-I-5 (G>C) mutation with haplotype IV (-+-++-+), codon 8/9 (+G) linked with haplotype I (+----++) were shown for the first time in Turkish population. The linkage of haplotype (+------) with the IVS-I-1 (G>A) mutation is reported for the first time in the published literature. In Denizli province of Turkey, beta globin gene cluster haplotypes of the normal population are strongly associated with the haplotypes of I (+----++), V (+----+-) and IX (-+-++++) respectively.

Rare hemoglobin variant Hb Yaizu observed in Turkey.

OBJECTIVE: To determine the characteristic features of the rare hemoglobin (Hb) variant Hb Yaizu to enable laboratory diagnosis of the hemoglobin variants during screening programs. MATERIALS AND METHODS: Genomic DNA was obtained from the 4 members of a family living in Denizli province, an Aegean region of Turkey. Blood cell counts, hemoglobin composition, hemoglobin electrophoresis (both alkaline and acid), HPLC analysis, DNA sequencing and beta globin gene cluster haplotypes were done. RESULTS: Hb Yaizu carriers were apparently healthy individuals. Hb Yaizu was slightly faster than Hb S at alkaline pH, but slower than Hb S at acidic pH in hemoglobin electrophoresis. An abnormal hemoglobin peak was observed with a retention time of 4.77 min in HPLC analysis attributed to Hb Yaizu. Two members of the family were heterozygous Hb Yaizu [beta 79(EF3) Asp>Asn] confirmed by DNA sequencing. The mutation was found to be linked with the Mediterranean haplotype I [+----++]. CONCLUSION: We have presented the details of Hb Yaizu, a rare hemoglobin variant that may be important to hemoglobinopathy screening programs, although its clinical significance is unclear.

First observation of Hb D-Ouled Rabah [beta19(B1)Asn>Lys] in the Turkish population.

Hb D-Ouled Rabah [beta19(B1)Asn>Lys] is a rare hemoglobin (Hb) beta chain variant reported from Tuareg tribes in Algeria and once from China. It was suggested that Hb D-Ouled Rabah might be specific of Berber-speaking populations. Our report describes the first observation of this hemoglobin variant in the Turkish population.

HLA-B51 gene and its expression in association with Behçet's Disease in Denizli Province of Turkey.

Behçet's Disease (BD) is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration, and uveitis with unknown pathogenesis. Many researchers have tried to investigate the association of HLA-B51 gene with the BD. We aimed to investigate the association of the HLA-B51 gene and its expression, also polymorphic structure by PCR, RT-PCR and sequence specific oligonucleotide primers and probes in BD patients (n: 35) and control group (n: 50). According to our results, we did not observe any association in between HLA-B51 gene, its polymorphism, expression and BD patients.

Beta globin gene cluster haplotypes of abnormal hemoglobins observed in Turkey.

Since the first observation of hemoglobin S (Hb S) in Turkey by Aksoy, the number of hemoglobin variants reported was increased. Beta globin gene cluster haplotypes are being used to determine the origin of the mutations under interest. We studied the beta globin gene cluster haplotypes for the six different abnormal hemoglobins which are Hb S, Hb D-Los Angeles, Hb G-Coushatta, Hb E, Hb E-Saskatoon and Hb J-Iran observed in Turkey. In this study, we report two novel haplotypes [- + + - - - +] and [- + - + + +] in association with the Hb G-Coushatta mutation. The haplotype for the Hb J-Iran is also reported as [- + - + + + +] for the first time in world populations from 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.

Molecular identification of a rare hemoglobin variant, Hb J-Iran [beta77(EF1)His->Asp], in Denizli province of Turkey.

Hb J-Iran [beta77(EF1)His-Asp], a rare hemoglobin variant that does not present health problems, was reported for the first time in the Turkish population in 1986. Our case is the fourth case reported in Turkey and the first case from the Denizli province.

Angiotensin-converting enzyme I/D polymorphism in Behçet's disease.

OBJECTIVE: To investigate a potential relationship between I/D polymorphism within intron 16 of the angiotensin-converting enzyme (ACE) gene located on human chromosome 17 and Behçet's disease. MATERIALS AND METHODS: Genomic DNA was obtained from 35 Turkish patients diagnosed with Behçet's disease according to the International Study Group criteria and 150 healthy individuals. Polymerase chain reaction was used to detect the presence of I and D (insertion and deletion) alleles in intron 16 of the ACE gene in these DNA samples. RESULTS: We found differences in ACE I/D polymorphism between Behçet's disease and healthy controls (chi2=4.61, d.f.=1, p=0.044). In Behçet's disease patients, the D allele frequency was 84.3% and I allele frequency 15.7%. CONCLUSION: An association between Behçet's disease and ACE polymorphism may provide a useful basis for future molecular studies and therapeutic approaches in this complex disease.

Beta-thalassemia mutations in Denizli province of Turkey.

Beta-thalassemia is one of the most common genetic disorders in Turkey as well as in several other Mediterranean countries presenting microcytosis and hemolytic anemia. The city of Denizli is located in the inner part of the Aegean geographical region of Turkey. The beta-thalassemia incidence in Denizli province is in between 2.6-3.7% reported by different researchers. According to our results; the IVS-1/nt-110 (G>A) is the most frequent mutation type in our province the same as other geographical regions of Turkey. Here we report also two HbD-Los Angeles/beta-thalassemia combinations, which are HbD-Los Angeles/codon 39 (C>T) and HbD-Los Angeles/IVS-1/nt-1 (G>A), respectively. In conclusion, our preliminary results show the heterogeneity of the beta-thalassemia mutations in the province of Denizli.

The angiotensin converting enzyme I/D polymorphism in Turkish athletes and sedentary controls.

The angiotensin converting enzyme (ACE) gene is located on human chromosome 17 expressing three genotypes within the intron 16 of the related gene structure. These genotypes are classified as I and D alleles which are termed as insertion and deletion, respectively. This study was carried out to identify possible relationships between the insertion/deletion (I/D) polymorphisms and athletic performance in Turkish athletes. To be able to determine these relationships, eighty healthy athletes and eighty healthy sedentary controls were genotyped for the ACE I/D polymorphism at gene level. According to the results obtained, we found significant difference on ACE I/D polymorphism in between athletes and healthy controls (x2 = 7.32, df = 2, P = 0.026). This result supports the association in ACE genotype in Turkish athletes, suggesting that this might be a genetic factor influencing the physical performance.