Ahmet Genc

Comparison of microscopic examination, rK39, and PCR for visceral leishmaniasis diagnosis in Turkey

The laboratory diagnosis of visceral leishmaniasis is based on microscopic examination, culture, serological tests, and molecular methods. In this study, we examined 50 blood specimens from suspected visceral leishmaniasis patients by microscopic examination, recombinant antigen dipstick test (rK39), and polymerase chain reaction (PCR) in the University of Cukurova, Faculty of Medicine, Parasitology Department in Turkey. We calculated the sensitivity–specificity and positive–negative predictive values for these diagnostic tests. We found that positive predictive value of microscopy examination, rK39 dipstick test, and PCR were 20%, 24%, and 58% for visceral leishmaniasis, respectively. When we compared polymerase chain reaction, recombinant antigen dipstick test, and microscopic examination for visceral leishmaniasis diagnosis, the polymerase chain reaction is more sensitive (100%) than recombinant antigen dipstick test and microscopy examination.

Detection of Plasmodium vivax by Nested PCR and Real-Time PCR

Malaria is endemic in the Cukurova region while it is sporadic in other regions of Turkey. Therefore, the laboratory and clinical diagnosis of malaria is important for the treatment of malaria. In this study, 92 blood samples that were taken from the suspected malaria patients for routine diagnosis in a period of 10 years between 1999 and 2009 were analyzed. All of these blood samples were examined by microscopic examinations using Giemsa-stained thick blood films, nested PCR, and real-time PCR. The sensitivity-specificity and positive-negative predictive values for these diagnostic tests were then calculated. It was found that the positive predictive values of microscopic examination of thick blood films, nested PCR, and real-time PCR were 47.8%, 56.5%, and 60.9% for malaria, respectively. The real-time PCR was found to have a specificity of 75% and sensitivity of 100%, while specificity and sensitivity of nested PCR was found 81.2% and 97.7% according to the microscopic examination of thick blood films, respectively.

Prevalence of β-Thalassemia Trait and Abnormal Hemoglobin in Premarital Screening in the Province of Izmir, Turkey

Background/Aims: Thalassemia is one of the most common hereditary disorders in Turkey. The aim of our study was to determine the prevalence of the β-thalassemia trait and abnormal hemoglobin in couples who applied for premarital screening in the third largest Turkish province of Izmir in the Aegean region. Methods: From January 2011 to March 2012, we tested 19,277 couples at the Karşıyaka Public Health Laboratory, Thalassemia Unit for the β-thalassemia trait and abnormal hemoglobin using a high-performance liquid chromatograph, a hematology analyzer. Results: The β-thalassemia trait with increased HbA2 (>3.5%) and abnormal hemoglobin was found in 4.96% (1912/38,554) and 0.53% (206/38,554) people, respectively. Of abnormal hemoglobin findings, HbS was determined in 128 people (0.33%), HbD in 50 (0.13%), HbE in 24 (0.06%), and HbC in four (0.01%). Furthermore, in 20 of the 19,277 couples (0.05%), both partners had the β-thalassemia trait and were referred to counseling. Conclusion: The prevalence of the β-thalassemia trait in the province of Izmir is high compared with other cities of Turkey. Izmir is a high-risk province for β-thalassemia and sickle-cell anemia. Therefore, premarital screening is essential to prevent new hereditary hemoglobinopaties.

Prevalence of Beta-Thalassemia Trait and Abnormal Hemoglobins in the Province of Adıyaman, Turkey

Background/Aims: Thalassemia is one of the most common hereditary disorders in Turkey. The aim of this study was to determine the prevalence of the beta-thalassemia trait and abnormal hemoglobins in the province of Adıyaman in Turkey. Methods: The study included 3571 high school students of both sexes; aged 12–22 (mean 16.59 ± 1.34). After they received information about thalassemia, they were screened for beta-thalassemia and abnormal hemoglobin using complete blood count (CBC) and quantification of hemoglobin. Hemoglobin was fractionated using HPLC. Results: The beta-thalassemia trait was found in 38 students (1.06%), and abnormal hemoglobin in seven students (0.20%). Of the latter, four carried HbD Los Angeles, two HbS, and one HbE-Saskatoon. Conclusion: The prevalence of the beta-thalassemia trait and abnormal hemoglobin in the province of Adıyaman is low, compared to the rest of Turkey. Our results seem to reflect the heterogeneity of beta-thalassemia in the province of Adıyaman and may be of value for genetic counseling and premarital screening.

Prevalence and Molecular Analysis of β-Thalassemia in Adiyaman, Turkey

Thalassemia is one of the most common hereditary disorders in the Mediterranean region. We report here the results of a premarital screening carried out in Adıyaman in the southeastern region of Turkey, a region with a hitherto unknown incidence of β-thalassemia (β-thal). In order to detect β-thal carrier frequency and genotypes of carriers from the city of Adıyaman, Turkey, both high performance liquid chromatography (HPLC) and the red blood cell counts of 1616 people who applied for premarital tests were analyzed. Blood cell counts were measured by a cell counter and the hemoglobin (Hb) fractionation was carried out by HPLC. The frequency of β-thal carriers in the city of Adıyaman was 1.91% and the frequency of abnormal Hbs was 0.07%. We report 28 chromosomes of β-thal traits with 10 different mutations, including the first report of codon 17 (AAG>TAG) in Turkey and one individual who was heterozygous for Hb D-Los Angeles [β121(GH4)Glu→Gln, GAA>CAA]. This study was the first to be performed on the frequency and molecular pathology of β-thal mutations in Adıyaman in the southeastern region of Turkey. We report that the prevalence of the thalassemia trait is similar in all regions of our country, but the prevalence of mutation heterogeneity varies from region to region.

NONSENSE β-THALASSEMIA MUTATION AT CODON 37 (TGG>TGA), DETECTED FOR THE FIRST TIME IN THREE TURKISH CASES

Thalassemias are genetically heterogeneous group of disorders with reduced or absent production of globin. β-Thalassemia major can be caused by homozygosity or compound heterozygosity for β-globin gene mutation. Here we report, for the first time in Turkey, three cases who carry the nonsense β-thalassemia (β-thal) mutation at codon 37 (TGG>TGA; Trp→Stop) causing premature stop codon.

Polymorphisms in human telomerase reverse transcriptase (hTERT) gene and susceptibility to gastric cancer in a Turkish population: Hospital-based case–control study

Erosion of telomeres, tandem nucleotide repeats (TTAGGG)n that cap the end of eukaryotic chromosomes, has been related with carcinogenesis. The human telomerase reverse transcriptase (hTERT) gene is encoded the rate-limiting catalytic subunit of the telomerase complexes, which is essential for the protection of telomeric DNA length and chromosomal stability. The purpose of this study was to examine the effect of four functional single nucleotide polymorphisms (SNPs) of hTERT (rs2736109 G>A, rs2735940 T>C, rs2853669 A>G and rs2736100 T>G) on susceptibility to gastric cancer (GC) in Turkish population. The genotype frequency of hTERT rs2736109 G>A, rs2735940 T>C, rs2853669 A>G and rs2736100 T>G polymorphisms were determined by using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and TaqMan methods in 104 subjects with GC and 209 healthy control subjects. We found that hTERT rs2736109 G>A (AA+AG vs. GG OR=1.68 95% CI=1.01-2.81, P=0.04), rs2735940 T>C (CC vs. CT+TT: OR=2.53 95% CI=1.01-6.13, P=0.03), and rs2736100 T>G (TT vs. TG+GG: OR=2.27 95% CI=1.23-4.17, P=0.006) polymorphisms were associated with risk of GC. In the haplotype analysis, hTERT Grs2736109/Trs2735940/Ars2853669/Grs2736100 haplotype was also related with an increased risk of GC (OR=1.75; 95% CI: 1.05-2.93, P=0.03). Because this is the first study regarding the hTERT rs2736109 G>A, rs2735940 T>C, rs2853669 A>G and rs2736100 T>G polymorphisms and the risk of GC susceptibility in the literature, further independent studies are needed to verify our results in a larger sample sizes, as well as in patients of different populations.

Prevalence of β-Thalassemia Trait and Abnormal Hemoglobins in Sanliurfa Province in Southeast Turkey

Abstract Thalassemia is one of the most common hereditary disorders in Turkey, especially in the Mediterranean region of the country. The purpose of this study was to determine the frequency of the β-thalassemia (β-thal) trait and abnormal hemoglobins (Hbs) in couples who applied for premarital screening in Sanliurfa Province, in the southeastern region of Turkey, a province with the first reported incidence of β-thal and abnormal Hbs. In the present study, in order to detect the prevalence of the β-thal trait and abnormal Hbs in Sanliurfa Province, Turkey, a total of 37,962 couples who applied for premarital screening were analyzed. From January 2011 through March 2014, red blood cell (RBC) counts and Hb fractionation were carried out by a cell counter and high performance liquid chromatography (HPLC), respectively. The prevalence of β-thal with high Hb A2 (>3.5%) values was found at rates of 2.44% (n = 1853) in Sanliurfa Province. Additionally, the abnormal Hb rate was 1.57% (1193/75,924), and Hb S (HBB: c.20T > A), Hb C (HBB: c.19G > A) and Hb D-Punjab (HBB: c.364G > C) were reported as 0.50, 0.38 and 0.69, respectively. This study is the first to establish the frequency of β-thal and abnormal Hbs in Sanliurfa Province, which has the highest birth frequency. We report that the frequency of the β-thal trait is at a high-risk level compared to other cities in Turkey. Due to the high risk of β-thal in Sanliurfa Province, a premarital screening program would be of great value in informing parents about offspring with β-thal.

Two rare hemoglobin variants in the Çukurova Region of Turkey: Hb E-Saskatoon and Hb G-Coushatta.

Hb E-Saskatoon and Hb G-Coushatta are rare hemoglobin variants that are not a health problem. Herein we present a Turkish woman that was diagnosed as homozygous Hb E-Saskatoon (only the second such case reported from Turkey) and a Turkish boy diagnosed as heterozygote Hb E-Saskatoon. Additionally, 2 Turkish sisters diagnosed as heterozygote Hb G-Coushatta are presented.

Effect of p53 Arg72Pro polymorphism on the induction of micronucleus by aflatoxin B1 in in vitro in human blood lymphocytes

Abstract Aflatoxin B1 (AFB1) is a class 1 carcinogen produced by Aspergillus flavus and Aspergillus parasiticus that can contaminate a variety of food substances, the liver being its target organ. A common p53 Arg72Pro polymorphism resulting in the substitution of an arginine amino acid by proline amino acid in the transactivating domain has been demonstrated to affect p53 function. The aim of this study is to investigate association between p53 Arg72Pro polymorphism and the frequencies of spontaneous and AFB1-induced DNA damage in peripheral blood lymphocytes from 100 healthy individuals in Turkish population. In vitro cytokinesis-blocked micronucleus (CBMN) assay was used to detect the spontaneous and AFB1-induced DNA damage whereas, genotyping of p53 Arg72Pro polymorphism was carried out by using a polymerase chain reaction restriction fragment length polymorphism assay. During 68 h incubation time, lymphocytes treated with AFB1 (1.56 μg/mL) and S9 mix for a total of 3 h (48–51 h). Treatment of the lymphocytes with AFB1significantly increased the overall frequencies of micronucleus (MN) when compared to untreated cultures (1.23 ± 0.05 versus 0.55 ± 0.02; p < 0.001). Moreover, genotype analysis revealed a statistically significant association between Pro/Pro genotype of p53 Arg72Pro polymorphism and increased frequencies of MN both spontaneous and AFB1-induced cultures when compared Arg/Arg genotype (0.69 ± 0.19 versus 0.46 ± 0.13, p < 0.001; 1.59 ± 0.65 versus 1.01 ± 0.41 p < 0.001; respectively). Our data indicate that p53 Arg72Pro polymorphism plays a significant role in human sensitivity to the genotoxic effects of AFB1. Further investigations in larger sample size and with different ethnic origins as well as including more functional single nucleotide polymorphisms might lead to the identification of novel genetic factors responsible for susceptibility to human carcinogens such as AFB1.