Radiological and Genetic Evaluation in Hypotonic Infants

OBJECTIVE

To investigate the importance and diagnostic yield of genetic and radiological evaluations in children with hypotonia.

STUDY DESIGN

Comparative observational study. Place and Duration of the Study: Department of Pediatrics Neurology, Namik Kemal University, Tekirdag, Turkey, between 2019 and 2022.

METHODOLOGY

Patients' medical histories, laboratory results, radiological examinations, and genetic tests, if any, were obtained retrospectively from the patients' clinic files. Children with hypotonia detected since the infantile period and who were on regular follow-up were included in the study. Patients who lost the follow-up were excluded.

RESULTS

Out of one hundred and seventy patients, 61.8% (n=105) were boys and 38.2% (n=65) were girls. The admission age of the patients ranged from 1 to 121 months; the mean age at presentation was 13.52±17.35 months. Hypotonia was central in 85.3% (n=145), peripheral in 12.4% (n=21), and mixed in 2.3% (n=4). Cerebral palsy was the predominant, non-genetic clinical cause of hypotonia (n=66, 39%). Brain magnetic resonance imaging (MRI) was normal in 48.2% (n=82). The most common MRI abnormality was periventricular leukomalacia in 15.9% (n=27). Sixty-five (38.2%) patients were diagnosed genetically. More than half of the patients with a genetic diagnosis were diagnosed by whole exome sequencing (WES).

CONCLUSION

Brain MRI is the first choice for the patients with central hypotonia. Patients who cannot be diagnosed with clinical findings and brain MRI should undergo WES. This is helpful for the long-term prognosis and management.

KEY WORDS

Hypotonia, Whole exome sequencing, Magnetic resonance, Spinal muscular atrophy, Cerebral palsy.

Silencing of TP73-AS1 impairs prostate cancer cell proliferation and induces apoptosis via regulation of TP73

BACKGROUND

Prostate cancer is a malignant disease that severely affects the health and comfort of the male population. The long non-coding RNA TP73-AS1 has been shown to be involved in the malignant transformation of various human cancers. However, whether TP73-AS1 contributes to prostate cancer progression has not been reported yet. Accordingly, here we aimed to report the role of TP73-AS1 in the development and progression of prostate cancer and determine its relationship with TP73.

METHODS AND RESULTS

TP73-AS1-specific siRNA oligo duplexes were used to silence TP73-AS1 in DU-145 and PC-3 cells. Results indicated that TP73-AS1 was upregulated whereas TP73 was downregulated in prostate cancer cells compared to normal prostate cells and there was a negative correlation between them. Besides, loss of function experiments of TP73-AS1 in prostate cancer cells strongly induced cellular apoptosis, interfered with the cell cycle progression, and modulated related pro- and anti-apoptotic gene expression. Colony formation and migration capacities of TP73-AS1-silenced prostate cancer cells were also found to be dramatically reduced.

CONCLUSIONS

Our findings provide novel evidence that suggests a chief regulatory role for the TP73-TP73-AS1 axis in prostate cancer development and progression, suggesting that the TP73/TP73-AS1 axis can be a promising diagnostic and therapeutic target for prostate cancer.

miR-320a promotes p53-dependent apoptosis of prostate cancer cells by negatively regulating TP73-AS1 invitro

TP73 antisense RNA 1 (TP73-AS1) is an oncogenic long non-coding RNA that is activated in several types of cancers. It has been shown that the activity of TP73-AS1 is controlled by several miRNAs, but post-transcriptional mechanisms that regulate TP73-AS1 activity in prostate cancer remain highly elusive. Accordingly, in the present study, we aimed to determine the miRNAs that are involved in the regulation of TP73-AS1 in prostate cancer and to show the effects of these molecules on the malignant proliferation of prostate cancer cells. Remarkably, colony formation and cell migration were suppressed while cell cycle arrest and apoptosis were induced in prostate cancer cells overexpressing miR-200a and miR-320a. miR-200a and miR-320a were found to be upregulated in TP73-AS1 suppressed prostate cancer cells. Also, TP73-AS1 was shown to be downregulated following miR-200a and miR-320a overexpression. However, overexpression of miR-320a had no significant effect on the expression of TP73. Further analysis revealed that miR-320a induces p53-dependent apoptosis. Consequently, our findings indicate that miR-320a induces p53-dependent apoptosis by negatively regulating TP73-AS1 long non-coding RNA.

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease.

Investigation of the Relationship between Autism Spectrum Disorder and FOXP2, GRIN2B, KATNAL2 and GABRA4 Genes

Introduction:

Autism spectrum disorder is a genetically and phenotypically heterogeneous group. Genetic studies carried out to date have suggested that both common and rare genetic variants play a role in the etiology of this disorder. In our study, we aimed to investigate the effect of FOXP2, GRIN2B, KATNAL2 and GABRA4 gene variants in the pathogenesis of autism spectrum disorder.

Method:

In our prospectively planned study, all exons and exon-intron junctions of FOXP2, GRIN2B, KATNAL2 and GABRA4 genes were screened by next generation sequencing analysis in 96 patients who diagnosed with autism spectrum disorder.

Results:

In our study, the average age was 10.1 and the male/female ratio was 75/21. Pathogenic or likely pathogenic variants were not detected in FOXP2, GRIN2B, KATNAL2 and GABRA4 genes, however, 69 intronic variants of unknown clinical significance were detected in 50 cases (52%). Among those, 26 were in the GABRA4 gene, 22 in the FOXP2 gene, 13 in the KATNAL2 gene, and 8 in the GRIN2B gene. Twenty three of these 69 variants were novel that were not previously reported in the literature.

Conclusion:

In our study, we could not identify a relationship between the autism spectrum disorder and FOXP2, GRIN2B, KATNAL2 and GABRA4 genes. Identifying genetic risk factors that play a role in the etiopathogenesis of autism spectrum disorder will contribute significantly to understanding the molecular mechanisms of the disease and the development of new treatment strategies. In this context, comprehensive molecular genetic studies such as whole exome or whole genome sequencing are required with higher number of cases in different populations.

Targeted next-generation sequencing as a diagnostic tool in gastrointestinal system cancer/polyposis patients

Background:

Recent advances in next-generation sequencing (NGS) technology have enabled multigene testing and changed the diagnostic approach to hereditary gastrointestinal cancer/polyposis syndromes. The aim of this study was to analyze different cancer predisposition genes in hereditary/sporadic gastrointestinal cancer/polyposis.

Methods:

Cancer predisposition genes were analyzed with an Illumina MiSeq NGS system in 80 patients with gastrointestinal cancer/polyposis who were examined between the years 2016 and 2019. Deletion/duplication analysis of MLH1, MSH2, and EPCAM genes was performed by using the multiplex ligation-dependent probe amplification method.

Results:

Germline testing of hereditary cancer-related genes was performed in 80 patients with gastrointestinal cancer/polyposis. A total of 30 variants in 30 cases (37.5%) were assessed as pathogenic/likely pathogenic. A total of 19 heterozygous variants were assessed as variants of uncertain clinical significance in 17 cases (21.25%) and 18 (22.5%) novel variations (9 pathogenic/likely pathogenic, 9 variants of uncertain significance) were determined. In 4 (5%) cases, multiplex ligation-dependent probe amplification detected deletions in MLH1, MSH2, and EPCAM genes.

Conclusion:

The accumulation of analyses with multigene testing will increase the available data for cancer predisposition genes in hereditary gastrointestinal cancer/polyposis. Educational campaigns for prevention, efficient screening programs, and more personalized care based on the profile of individual patients are necessary.

Next generation sequencing analysis of BRCA1 and BRCA2 identifies novel variations in breast cancer

Mutations in two major breast cancer susceptibility genes, BRCA1 and BRCA2, have been identified to be the most important predisposing factors for the development of breast cancer. Thus, BRCA1/2 testing is a well-established method of choice for the assessment of developing breast cancer. Accordingly, here we aimed to report novel BRCA1/2 variations and distribution of previously known mutations and their association with the clinical course of breast cancer disease. A total of 287 breast cancer patients were enrolled from January 2017 through December 2019. Of these patients, 50 of them were identified to be positive for BRCA1/2. Next Generation Sequencing analysis was performed for the screening of exonic and intronic variations of BRCA1/BRCA2 genes. Notably, novel variations of 4448 G > A (Ser1843Asn) in BRCA1, and 982dupA (Thr328AspfsTer) and 7588C > T (Gln2530Ter) in BRCA2 gene were identified. The most common variations in BRCA1 gene were 5152 + 66G > A, 442-34C > T and 5266dupC. In BRCA2 gene, the most common variations were 9097dupA, 67 + 1G > A and 1114A > C. Novel variations of BRCA1 and BRCA2 genes were identified in breast cancer and might be useful predisposing factors in breast cancer diagnosis.

Genetic screening results of individuals with high risk BRCA-related breast/ovarian cancer in Trakya region of Turkey

PURPOSE

Pathogenic/likely pathogenic (P/LP) germline variations in BRCA1 and BRCA2 genes are responsible for the majority of hereditary breast and ovarian cancers. This study presents the BRCA1/BRCA2 sequencing and deletion duplication analyses results of of 493 participants (485 women, 8 men) selected based on the National Comprehensive Cancer Network (NCCN) guidelines.

METHODS

Next generation sequencing (NGS) and multiplex ligation-dependent probe amplification methods (MLPA) were used to define germline BRCA1/BRCA2 positivity.

RESULTS

Overall, the P/LP frequency of the participants was 17.8%. Five of the likely pathogenic variants were novel. The 5266dupC pathogenic variation, which is a founder mutation in the Ashkenazi Jewish population, was the most common variation among the patients, with a frequency of 5.47%. The pathogenic/likely pathogenic variation frequency was significantly higher (p=0.01) among clinically diagnosed familial cancer patisents than those participants without personal history of cancer but enrolled for BRCA1 testing due to familial risk. BRCA1/BRCA mutation positivity was significantly higher (p=0.000) among those who had at least one first- or second-degree relative with breast/ovarian cancer from patients who had no family history. BRCA1/BRCA2 mutation positivity was 69.23% between the patients who had personal history of both breast and ovarian cancer.

CONCLUSION

Based on our findings, we suggest that sequencing all of the coding regions of the BRCA1/BRCA2 genes using NGS is a feasible approach for individuals who are at risk of developing BRCA-related cancer according to NCCN guidelines. The 5266dupC pathogenic variation, as the most common pathogenic variation in the Trakya region of Turkey, should be included if a targeted mutatin screening is planned.

Next-generation screening of a panel of genes associated with periodic fever syndromes in patients with Familial Mediterranean Fever and their clinical characteristics

Familial Mediterranean Fever (FMF) is a hereditary fever syndrome that primarily affects Mediterranean populations. For the study, total number of 182 patients with FMF disease were enrolled and screening of a panel of genes , called "fever panel" which comprises 17 genes, was performed. The most common mutations in MEFV gene were homozygous M694V missense mutation (4.3%) and R202Q missense mutation (4.9%). The most common heterozygous mutations were R202Q (26.5%), M694V (25.9%) and E148Q (11.9%). Compound heterozygous and homozygous mutations were also detected. Also, different types of mutations were identified in NOD2, CARD14, NLRP12, NLRP3, NLRP7, IL1RN, LPIN2, TNFRSF1A, MVK and PSTPIP1 genes. Two novel missense variations in the MEFV gene, Gln34Pro and Ile247Val, which have not been previously reported in the databases, were identified. Also, Thr91Ile missense variation in the NOD2 gene, Gly461Cys missense variation in NLRP3 and Tyr732Stop nonsense variation in LPIN2 were firstly identified. The results of the current study suggest that in addition to the MEFV gene which has an important roles in FMF, molecular screening of other genes related to other autoinflammatory diseases might provide support in suspected cases and provide detailed information about the course of the disease.

Nonoccupational Exposure of Agricultural Area Residents to Pesticides: Pesticide Accumulation and Evaluation of Genotoxicity

Although many studies related the toxic effects of pesticides on agricultural workers, little research has been done about agricultural area residents. The purpose of this work was to monitor the presence of pesticides, as well as their genotoxic and cytotoxic potential, in humans with blood samples collected from control and intensive agricultural areas in the Thrace region. Pesticide accumulations were determined by LC-MS/MS. Cytotoxicity and genotoxicity were analyzed by comet assay, and the effect of pesticide accumulation on oxidative stress, DNA repair, and molecular chaperone response were analyzed by qRT-PCR assays in the human blood samples. The agricultural area residents had a significantly higher concentration of pesticides than those in the control area at all three sampling times, and the total pesticide amounts were 4.3 and 10 times significantly higher in blood sampled in the pesticide use period (August 2015 and 2016, respectively) than in the nonuse period (November 2015). The results showed that the pesticide level in blood during the use period led to oxidative stress, DNA damage (mean comet length and % tail DNA), and unfolded/misfolded protein response. Particularly, in pesticide use season, difference between these parameters was found statistically significant with comparison to control. Our results indicate that individuals residing around a monoculture rice farming area comprise an at-risk group as a result of increased genotoxicity evidenced in human blood. We suggest that biological monitoring efforts should be used to control nonoccupational exposures to pesticides and thus safeguard the health of agricultural area residents.

Investigation of Copy Number Variation by arrayCGH in Turkish Children and Adolescents Diagnosed with Autism Spectrum Disorders

Aim

The development of whole-genome screening methodologies for the detection of copy number variations (CNVs), such as array-based comparative genomic hybridization (aCHG), provides a much higher resolution than karyotyping leading to the identification of novel microdeletion and microduplication syndromes often associated with an autism spectrum disease (ASD) phenotype. The aim of the study was to determine CNVs of patients with ASD by using array-based comparative genomic hybridization.

Methods

Fifty-three patients diagnosed with ASD between 20.01.2014 and 14.01.2015 were included in the study. Chromosome analysis of the patients was performed from peripheral blood cultures and analysed as normal. All patients were evaluated with P064C1 and P096A2 MLPA probes in terms of 16 mental retardation related syndromes. For aCGH method, SurePrint G3 Human microarrays 8x60K were used with genomic DNA isolated from peripheral blood.

Results

According to results of 53 patients who were included in and performed with arrayCGH, 8 (15%) patients had CNVs classified as pathogenic or variant of unknown significance (VOUS) in the study. We detected a pathogenic NRXN1 gene partial CNV deletion (2p16.3) in two patients. Also we identified a 900 kb duplication of 4p15.31 including SLIT2 gene, and a 245 kb duplication of 15q11.2 including PWRN1 gene in one patient. Our other findings are considered to be a variant of unknown significance (VOUS).

Conclusion

The results of the study support the literature knowledge, where the copy number variations that cannot be detected with conventional cytogenetics methods in terms of size may happen in patients with ASD.

BRAF V600 Mutation Profile of Metastatic Melanoma in the Thrace Region of Turkey

OBJECTIVE

BRAF is the most common mutation in melanoma. The most common subtype is BRAF V600E, followed by V600K. Initially, the authors aimed to investigate whether clinicopathological features of melanoma are associated with BRAF mutations. We then aimed to present the relationships between the clinicopathological features and the mutated subtype (V600E vs V600K).

MATERIAL AND METHOD

61 patients with metastatic malignant melanoma (affecting the lymph node or other distant sites) were selected. Patient data regarding age at the time of diagnosis, sex, metastatic site (lymph node, distant metastasis or both) and primary tumour site were obtained from the hospital's database. Tissue samples containing at least 30% tumour cells were isolated from the specimens of 61 patients (24 samples from primary tumours and 37 from metastatic foci) for BRAF analysis. Comparisons between the BRAF V600 mutation and clinicopathological and histopathological features were performed.

RESULTS

BRAF V600 mutation was detected in 34 (55.7%) patients. The subtype was BRAF V600E in 22 (64.7%) patients, BRAF V600K in 11(32.4%) patients and BRAF V600R in 1(2.9%) patient. The crucial results of the present study may be summarized as follows: i) BRAF V600 mutation was more common in older patients and tumors with BRAF V600 mutation revealed necrosis and LVI more commonly than wild-type tumors, ii) BRAF V600K mutation was more common in older patients and BRAF V600K mutated tumors exhibited ulceration more commonly than tumors with BRAF V600E mutation (close to significant).

CONCLUSION

The BRAF V600 mutation may have interactions with prognostic clinicoptahological features of melanoma including necrosis and lymphovascular invasion. V600K mutation may be more common than expected and may have different associations with properties of the tumor such as tumor ulceration and patient age. Investigation of the mutated subtype of the BRAF gene may therefore reveal more detailed data about the management of melanoma and may also prevent missing of candidates for BRAF inhibitor therapies.

BRAF V600 Mutation Profile of Metastatic Melanoma in the Thrace Region of Turkey

OBJECTIVE

BRAF is the most common mutation in melanoma. The most common subtype is BRAF V600E, followed by V600K. Initially, the authors aimed to investigate whether clinicopathological features of melanoma are associated with BRAF mutations. We then aimed to present the relationships between the clinicopathological features and the mutated subtype (V600E vs V600K).

MATERIAL AND METHOD

61 patients with metastatic malignant melanoma (affecting the lymph node or other distant sites) were selected. Patient data regarding age at the time of diagnosis, sex, metastatic site (lymph node, distant metastasis or both) and primary tumour site were obtained from the hospital's database. Tissue samples containing at least 30% tumour cells were isolated from the specimens of 61 patients (24 samples from primary tumours and 37 from metastatic foci) for BRAF analysis. Comparisons between the BRAF V600 mutation and clinicopathological and histopathological features were performed.

RESULTS

BRAF V600 mutation was detected in 34 (55.7%) patients. The subtype was BRAF V600E in 22 (64.7%) patients, BRAF V600K in 11(32.4%) patients and BRAF V600R in 1(2.9%) patient. The crucial results of the present study may be summarized as follows: i) BRAF V600 mutation was more common in older patients and tumors with BRAF V600 mutation revealed necrosis and LVI more commonly than wild-type tumors, ii) BRAF V600K mutation was more common in older patients and BRAF V600K mutated tumors exhibited ulceration more commonly than tumors with BRAF V600E mutation (close to significant).

CONCLUSION

The BRAF V600 mutation may have interactions with prognostic clinicoptahological features of melanoma including necrosis and lymphovascular invasion. V600K mutation may be more common than expected and may have different associations with properties of the tumor such as tumor ulceration and patient age. Investigation of the mutated subtype of the BRAF gene may therefore reveal more detailed data about the management of melanoma and may also prevent missing of candidates for BRAF inhibitor therapies.

Cytotoxic Antibody Detection by Means of Flow-Cytometric Cross-Match

BACKGROUND

Complement-dependent lymphocytotoxicity (CDC-XM) and flow-cytometric (FCXM) cross-match are analyzed individually for each donor and recipient pair, because these techniques have fundamental differences for the evaluation of histocompatibility. Lately, cytotoxic flow-cytometric cross-match (cFCXM) has been developed as an alternative to both CDC-XM and FCXM techniques. We evaluated the limits of cFCXM with the use of different positive serum dilutions.

METHODS

CDC-XM, FCXM, and cFCXM tests were performed with the use of commercially available negative and positive serum samples and lymphocytes from healthy donors.

RESULTS

Complement-dependent cell death was successfully detected with the use of cFCXM. Complement-dependent cell death ratios in cFCXM were similar those in CDC-XM. With cFCXM, not only complement-dependent cell death but also IgG binding could be detected within a single assay. At higher concentrations of the positive serum, IgG-fluorescein isothiocyanate (FITC) mean fluorescent intensity (MFI) values detected with the use of cFCXM were less than those of conventional FCXM. Correspondingly, for dead cells, MFI values of IgG-FITC were less than those of live cells in higher positive serum concentrations in the cFCXM assay. Moreover, our results demonstrated that in cFCXM analysis, the decreasing ratio of dead cells at increasing positive serum dilutions was not in parallel with the same decrease in IgG-FITC MFI values.

CONCLUSIONS

The cFCXM technique detects complement-mediated cytotoxic cell death with the additional ability to show IgG binding in the same tube and therefore may reduce the necessary bench time and workload.

Impact of active smoking on survival of patients with metastatic lung adenocarcinoma harboring an epidermal growth factor receptor (EGFR) mutation

Lung cancer in smokers and non-smokers demonstrates distinct genetic profiles, and cigarette smoking affects epidermal growth factor receptor (EGFR) function and causes secondary EGFR tyrosine kinase resistance. We evaluated the effect of active smoking in patients with metastatic lung adenocarcinoma. A total of 132 metastatic lung adenocarcinoma patients, diagnosed between 2008 and 2013, with known EGFR mutation status, were evaluated retrospectively. Among these patients, 40 had an activating EGFR mutation. Patients who continued smoking during the treatment were defined as active smokers. Former smokers and never smokers were together defined as non-smokers. The outcomes of the treatment in relation to the EGFR mutation and smoking status were evaluated. The median follow-up time was 10.5 months. The overall response rate for the first-line therapy was significantly higher among the EGFR-mutant patients (p = 0.01), however, smoking status had no impact on the response rate (p = 0.1). The EGFR-mutant active smokers progressed earlier than the non-smokers (p < 0.01). The overall survival (OS) of the non-smokers and patients treated with erlotinib was significantly longer (p = 0.02 and p = 0.01, respectively). Smoking status did not affect the OS in EGFR wild type tumors (p = 0.49) but EGFR-mutant non-smokers had a longer OS than the active smokers (p = 0.01).The active smokers treated with erlotinib had poorer survival than the non-smokers (p = 0.03). Multivariate analysis of EGFR-mutant patients showed that erlotinib treatment at any line and non-smoking were independent prognostic factors for the OS (p = 0.04 and p = 0.01, respectively). Smoking during treatment is a negative prognostic factor in metastatic lung adenocarcinoma with an EGFR mutation.

A case with Emanuel syndrome: extra derivative 22 chromosome inherited from the mother

Emanuel syndrome (ES) is a rare chromosomal disorder that is characterized by multiple congenital anomalies and developmental disabilities. Affected children are usually identified in the newborn period as the offspring of balanced (11;22) translocation carriers. Carriers of this balanced translocation usually have no clinical symptoms and are often identified after the birth of offspring with an unbalanced form of the translocation, the supernumerary der(22) t(11;22) syndrome. We report a 3-year-old boy with the t(11;22)(q23;q11) chromosome, transmitted in an unbalanced fashion from his mother. He has several developmental delays; he is not independently ambulatory and language is significantly impaired. Using his peripheral blood, karyotyping was performed to define his multiple congenital anomalies, revealing the following chromosomal abnormality: 47, XY, +der(22)t(11;22)(q23.3;q11.2). To ascertain the origin and trait of this supernumerary marker chromosome [der(22)t(11;22)(q23.3;q11.2)], karyotyping of his parents was performed. The mother was found to be a balanced carrier: 46, XX, t(11;22) (q23.3; q11.2).

Primary Tumor Resection Offers Higher Survival Advantage in KRAS Mutant Metastatic Colorectal Cancer Patients

BACKGROUND/AIMS

Colorectal cancer is the fourth most common cancer diagnosed in the United States, and the third most common cause of death from cancer. Approximately 20% of the patients with colorectal cancer have distant metastasis during diagnosis. Primary tumor resection is controversial in unresectable metastatic colorectal cancer (CRC). We studied the survival effect of primary tumor resection in unresectable metastatic CRC according to kirsten ras (KRAS) mutation status.

METHODOLOGY

Seventy eight CRC cases with unresectable metastasis were included in the study. The KRAS status was known in all patients. 34 patients had undergone primary tumor resection before 1st chemotherapy.

RESULTS

ThE median time from primary tumor resection to first chemotherapy was 6 (3-17) weeks. The survival was better in the unresectable metastatic colon patients with resected primary tumor, but it was statistically non-significant (P = 0.07). The median OS was similar (P = 0.91) in the KRAS wild patients with or without primary tumor resection. The median OS was 28 months in KRAS mutant patients with primary tumor resection, 14 months in KRAS mutant patients without primary tumor resection (P = 0.002).

CONCLUSION

Primary tumor resection offers survival advantage in KRAS mutant patients, but randomized prospective studies are required.

An Investigation of the Relationship between the eNOS Gene Polymorphism and Diagnosed Migraine

We investigated the phenotype-genotype association of the following endothelial nitric oxide synthase (eNOS) gene polymorphisms, rs743506, rs2070744, rs1799983, rs180079, rs3918226, rs207468799 and rs148554851, in patients suffering from migraine living in Edirne, Turkey. A total of 175 individuals, who had been diagnosed with migraine between April 2013 and December 2013, at the Neurology Department, Trakya University Medical Faculty, Edirne, Turkey, and 125 healthy controls were recruited. The above gene polymorphisms were analyzed from genomic DNA in both patient and control groups, using the pyro-sequencing method. The eNOS rs1799983 TT genotype frequency in migraine patients who had a headache duration of longer than 24 hours was statistically significantly higher than in patients who had migraine attacks that lasted under 24 hours (p = 0.047). In terms of the AGGTGGA haplotype, the severity of headache was statistically significant, and was found to be severe in 61.0% (p = 0.0001). Also in terms of the AGGTGGA haplotype, the duration of headache was statistically significant, and was >24 hours in 56.0% of patients (p = 0.008). In our study, there was no significant genotypephenotype relationship between eNOS rs743506, rs2070744, rs1799983, rs180079, rs3918226, rs207468799 and rs148554851 gene polymorphisms and migraine patients with and without aura living in Edirne, Turkey. The AGGTGGA haplotype constitutes a risk in terms of the severity and the duration of headaches in patients with migraine. This risk is significantly higher in patients with migraine with aura than patients with migraine without aura.

Identification of a novel HLA-A*26 allele, HLA-A*26:01:36, in a Turkish family by sequence-based typing

HLA-A*26:01:36 differs from the closest allele HLA-A*26:01:01 by a nucleotide change at the position 114.

Association between specific KRAS mutations and the clinicopathological characteristics of colorectal tumors

The aim of this study was to investigate the clinicopathological characteristics and distribution by tumor localization of KRAS point mutations in metastatic colorectal cancer. A total of 189 patients diagnosed with colorectal cancer between 2007 and 2014, who were either metastatic at the time of diagnosis or developed metastasis subsequently, were included in this study. KRAS mutation analysis was performed in the primary tumor tissues and KRAS mutations were identified in 47.6% of the patients. There was a high frequency of the p.G13D point mutation in left-colon tumors (P=0.011), while the p.G12D point mutation was more frequent in right-colon tumors (P=0.004). KRAS wild-type frequency (P=0.02) was higher among patients aged <40 years. A comparison of codon 12 and 13 mutations revealed that codon 12 mutations were more common in the >50-year-old group (P=0.03) and codon 13 mutations were more common in the <70-year-old group (P=0.04). KRAS wild-type tumors were localized in the right colon (P=0.005) and tumors with the p.G13D point mutation (P=0.018) were diagnosed at non-metastatic stages. In conclusion, KRAS point mutations in colorectal cancer exhibited a heterogeneous distribution in terms of tumor localization. In addition, the p.G13D point mutation was found to differ from other mutations in several aspects.

The presence of donor-specific antibodies in renal transplantation

Determining the presence of anti-HLA antibodies before transplantation is an important factor to prevent loss of function among renal transplantations. In addition, recent studies have shown that not only the pretransplantation existence of anti-HLA antibody but also posttransplantation donor-specific antibodies (DSA) and non-donor-specific antibodies are significantly associated with allograft rejection or loss of graft function. This study presented DSA among patients after renal transplantation together with graft function and survival.

Effect of leptin and apelin preconditioning on hepatic ischemia reperfusion injury in rats

Leptin and apelin are important adipocytokines involved in a variety of endocrine and paracrine functions. The aim of this study was to evaluate the effect of exogenous leptin and apelin preconditioning on hepatic ischemia reperfusion (I/R) injury in rats. Forty mice were assigned to four groups (n = 10): sham-operated control (sham), I/R injury, I/R + leptin (I/R + L), and I/R + apelin (I/R + A). Leptin 100 μg/kg/day and apelin 2 μg/kg/day were delivered intraperitoneally starting 3 days prior to surgical procedure in I/R + L and I/R + A groups, respectively. All I/R groups underwent 45 min of warm ischemia, followed by 30 min of reperfusion. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver malondialdehyde (MDA) and glutathione (GSH), and liver histopathology were compared between groups. MDA was elevated in I/R, but stayed similar in I/R + L and I/R + A compared to sham. I/R + A had significantly lower MDA compared to I/R. GSH levels did not differ significantly between the groups. ALT and AST were elevated in all I/R groups, but significant reduction was observed in I/R + L and I/R + A compared to I/R. Liver histopathology was mostly mild in I/R + L and I/R + A, in contrast to severe injury observed in the I/R group. Leptin and apelin preconditioning significantly reduced hepatic I/R injury in rats.

No association of KIR genes with Behcet's disease

Behcet's disease (BD) is thought to be caused by multiple genetic, environmental and immunological factors, one of the most prominent being the strong association with human leucocyte antigen (HLA)-Bw51, an HLA-Bw4-associated allele. We examined the presence/absence of 14 killer cell immunoglobulin-like receptors (KIRs) and their ligands in 134 Turkish individuals with BD and compared the results with those of 154 ethnically matched controls. Although KIR3DL1 with its ligand (HLA-Bw4) was significantly increased in the patients with BD (P = 0.0003), this no longer applied when the patients and controls were categorised by HLA-Bw51 status. Thus, no association was identified between presence or absence of any of the 14 KIR genes studied and BD. In addition, we did not find any associations of KIR with various manifestations of the disease nor with gender or age of onset.

HLA system affects the age-at-onset in chronic myeloid leukemia

Chronic myeloid leukemia (CML) occurs from childhood to old age. The adult form is characterized by the presence of Philadelphia chromosome resulting from bcr/abl translocation. The BCR-ABL fusion proteins are immunogenic, and the junctional sequences show unique HLA class I and class II restriction patterns in vitro. A previous study in the west of Scotland showed an influence of several HLA genotypes on the age-at-onset of CML. In the present study, we examined the HLA-A, -B, and -DRB1/3/4/5 allele and haplotype distributions in Turkish CML patients diagnosed in a single center where they are routinely HLA-typed by PCR-SSP analysis as a preparation for stem cell transplantation. The patients were 169 subjects of age 17-60 years. The older patients were not HLA typed and missing from the study group. The age-matched control group (n = 213) was healthy blood donors from the same geographical area. HLA-B*37 showed a risk association with CML [P = 0.02; odds ratio (OR) = 5.35]. The DRB1*10 association at similar magnitude was due to its linkage disequilibrium (LD) with B*37. HLA-B*35 and DRB1*11 showed independent protective effects (P = 0.007 and 0.017; OR = 0.54 and 0.60, respectively). The protective association of DRB1*11 may be due to its involvement in the presentation of the common (b3a2) fusion gene. HLA-B*14 and DRB1*01 showed strong LD, and all 5 patients who were positive for the presumed haplotype B*14-DRB1*01 were of age 43 years old or older (P = 0.003), suggesting a delay effect. We also examined the influence of homozygosity for DRB3 (DR52) and DRB4 (DR53) haplotypes on susceptibility. As previously shown in CML and CLL, DRB4 homozygosity was a risk marker (P = 0.01; OR = 3.36), and DRB3 homozygosity was protective (P = 0.007; OR = 0.51). Despite the lack of elderly patients in the study group, the opposite accelerating (DRB4) and delaying (DRB3) effects of homozygous genotypes on the age-at-onset were evident. Besides replicating previously found associations in a different population, this study also suggested new, and probably population-specific associations in CML. The mechanisms by which the HLA system modifies susceptibility to CML are unknown, likely to include immune and nonimmune ones, and worthy of further studies.