Salih Coşkun

Comparison of plasma MicroRNA levels in drug naive, first episode depressed patients and healthy controls

Major depression is the most common psychiatric disorder. The diagnosis of depression depends on a patients subjective complaints, and the nature of the heterogeneous disorder. Thus, there is no known biomarker for depression to date. Previous research has indicated that microRNAs are dysregulated in bipolar disorder and schizophrenia. We aimed to investigate microRNA dysregulation in plasma samples of patients with major depression. Venous blood samples of 50 depressed patients and 41 healthy controls were collected and the quantification of microRNAs was established using qRT-PCR. We found miR-320a significantly downregulated and miR-451a significantly upregulated in depressed patients. We also found miR-17-5p and miR-223-3p upregulated, but not as significantly as miR-451a. Merging our results with previous published data shows that the blood miR-320 family may be a potential microRNA family dysregulated in major depression. Research should be performed on miR-320-related pathways and their relationship to depression. Additionally, miR-451a could serve as a candidate biomarker for depression based on the acting mechanism of ketamine. Studies targeting miR-451a levels before and after treatment could be helpful.

Association of polymorphisms in the vitamin D receptor gene and serum 25-hydroxyvitamin D levels in children with autism spectrum disorder

Vitamin D is implicated in several aspects of human physiology, and polymorphisms in the vitamin D receptor gene (VDR) are associated with a variety of neuropsychiatric disorders. The aims of this study are to determine whether VDR polymorphisms are associated with autism spectrum disorder (ASD), to examine serum 25-hydroxyvitamin D (25(OH)D) levels in ASD, and to explore whether VDR polymorphisms influence serum 25(OH)D levels. We investigated 480 subjects (237 children with ASD and 243 healthy controls) for the following VDR polymorphisms: TaqI, BsmI, FokI, ApaI, and Cdx2.Within the same samples, 25(OH)D levels were available only for 85 patients and 82 controls. The Cdx-2 variation was shown to deviate from Hardy-Weinberg equilibrium in the controls and was therefore excluded from the study. We found that the frequency of rare FokI TT, TaqI CC, and BsmI AA genotypes differed significantly between children with ASD and the controls (p=0.042, p=0.016, p=0.038, respectively). After correction for multiple testing, only the TaqI CC genotype remained significant. Further analysis using a recessive model showed that rare genotypes of these polymorphisms were significantly higher in patients compared to controls (p=0.045, p=0.005 and p=0.031, respectively). However, no significant association was found between ApaI and ASD. We found serum 25(OH)D levels to be significantly higher in children with ASD (p<0.001) and that the FokI polymorphism had an effect on serum 25(OH)D levels in children with ASD (p=0.041). Additionally, we found the haplotype GTTT (BsmI/TaqI/FokI/ApaI) conferred an increased risk for developing ASD (p=0.022; odds ratio [95% confidence interval]=2.322 [1.105-4.879]). This is the first clinical study evaluating the association between serum 25(OH)D levels and VDR polymorphisms in children with ASD. Our results demonstrated a significant association between TaqI, BsmI, and FokI polymorphisms and ASD and showed for the first time that FokI polymorphisms and haplotype GTTT (BsmI/TaqI/FokI/ApaI) are associated with an increased risk of ASD. Our findings support the hypothesis that 25(OH)D is involved in the pathophysiology of autism and that serum 25(OH)D levels may be affected by FokI polymorphisms in children with ASD. Our results should be considered as preliminary and needs confirmation by future studies.

Romano-Ward sendromunda KCNQ1 geninde bir duplikasyon mutasyonu

Long QT syndrome (LQTS), a rare congenital cardiac condition associated with life‐threatening ventricular arrhythmias is characterized by a prolonged QT interval on electrocardiograph corrected for heart rate [corrected QT (QTc)]. LQTS has been historically categorized into the autosomal dominant Romano–Ward syndrome (RWS) and the autosomal recessive Jervell and Lange‐Nielsen syndrome (JLNS). JLNS is associated with prelingual sensorineural deafness. Both types of LQTS can be caused by mutations in channel genes (e.g. KCNQ1) responsible for potassium homeostasis in cardiac myocytes and cochlea. Autosomal dominant mutations often cause the RWS phenotype and homozygous or compound heterozygous mutations contribute to JLNS. Two First Nations communities in northern British Columbia are affected disproportionately with LQTS largely due to the V205M mutation in KCNQ1, however, the pathology and phenotypic expression for those V205M homozygous has been unknown. Here, we show that four V205M homozygous individuals have a significantly higher ‘peak’ QTc, and a more severe cardiac phenotype compared with 41 V205M heterozygous carriers and 57 first to third degree relatives without mutations. Given the lack of prelingual deafness the homozygous V205M LQTS patients present with a phenotype more typical of RWS than JLNS.

Association of brain-derived neurotrophic factor and nerve growth factor gene polymorphisms with susceptibility to migraine

Migraine is one of the most common neurological diseases worldwide. Migraine pathophysiology is very complex. Genetic factors play a major role in migraine. Neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), play an important role in central nervous system functioning, development, and modulation of pain. This study investigates whether polymorphisms in the BDNF and NGF genes are associated with migraine disease in a Turkish case–control population. Overall, 576 subjects were investigated (288 patients with migraine and 288 healthy controls) for the following polymorphisms: rs6265(G/A), rs8192466(C/T), rs925946(G/T), rs2049046(A/T), and rs12273363(T/C) in the BDNF gene, and rs6330(C/T), rs11466112(C/T), rs11102930(C/A), and rs4839435(G/A) in the NGF gene using 5′-exonuclease allelic discrimination assays. We found no differences in frequency of the analyzed eight polymorphisms between migraine and control groups. However, the frequency of minor A alleles of rs6265 in BDNF gene was borderline significant in the patients compared with the healthy controls (P=0.049; odds ratios [ORs] [95% confidence intervals {CIs}] =0.723 [0.523–0.999]). Moreover, when the migraine patients were divided into two subgroups, migraine with aura (MA) and migraine without aura (MO), the minor TT genotype of rs6330 in NGF was significantly higher in MA patients than in MO patients (P=0.036) or healthy controls (P=0.026), and this disappeared after correction for multiple testing. Also, the rs6330*T minor allele was more common in the MA group than in the MO group or controls (P=0.011, ORs [95% CIs] =1.626 [1.117–2.365] or P=0.007, ORs [95% CIs] =1.610 [1.140–2.274], respectively). In conclusion, this is the first clinical study to evaluate the association between BDNF and NGF polymorphisms in migraine patients compared with health controls. Our findings suggest that the NGF rs6330*T minor allele might be nominated as a risk factor for developing aura in migraine disease. Our results should be considered as preliminary, and they need to be confirmed by future studies.

High frequency of E148Q sequence variation in children with familial Mediterranean fever in southeast Turkey

OBJECTIVE The aim of this study was to investigate the spectrum of Mediterranean fever (MEFV) gene mutations and genotype-phenotype correlation in children with familial Mediterranean fever (FMF) in southeast Turkey. METHODS A total of 507 children (274 females) with FMF and MEFV gene mutation(s) were included. A 15-year retrospective evaluation was conducted; parameters analyzed were: age, sex, age at symptoms onset, age at FMF diagnosis, delay between symptoms onset and diagnosis, FMF attack symptoms, and response to colchicine. Disease severity scores were calculated and MEFV mutation analysis was performed via real-time PCR for the 6 most frequent mutations. Children with comorbid diseases or tested negative for MEFV gene mutations were excluded to provide homogeneity. RESULTS A family history of FMF was found in 60.2% (n=305) of patients. The most common symptoms reported for FMF attacks were abdominal pain (98.0%), fever (93.9%) and arthralgia (47.3%); 75.0% of patients (n=380) were heterozygous, 14.2% were homozygous (n=72) and 10.8% were compound heterozygous (n=55).The following MEFV gene mutation alleles were identified: E148Q (40.1%), M694V (25.9%), V726A (15.8%), R761H (7.4%), M680I (6.8%), and P369S (4.1%). The M694V subgroup had the lowest mean age of disease onset and the highest mean disease severity score, whereas the E148Q group had later mean disease onset and the lowest mean disease severity score (p<0.05). CONCLUSION The highest E148Q mutation frequency and milder disease in the course of FMF in our study population may be due to geographic and ethnic background dissimilarities of southeast Turkey.

Insecticide imidacloprid influences cognitive functions and alters learning performance and related gene expression in a rat model.

The potential toxic effects of several pesticides, including imidacloprid on non‐target organisms have not been clearly established. Also, the chronic effects of non‐toxic doses on cognitive function in mammals are unknown. In this study, the effects of different doses of imidacloprid on learning and memory of infant and adult rats were evaluated, and the expressions of genes synthesizing proteins known to be associated with learning in brain tissues were also documented. 0.5, 2 and 8 mg/kg doses of imidacloprid were administered to newborn infant and adult Wistar albino rats by gavage. Their learning activities were evaluated, and the expression levels of the inotropic glutamate receptor GRIN1, synoptophysin, growth‐associated protein 43 and the muscarinic receptor M1 in hippocampus were determined by real‐time PCR method. Learning activities were diminished significantly at 2 and 8 mg/kg doses in the infant model groups and at 8 mg/kg dose in adult rats. Also, expression levels of GRIN1, SYP and GAP‐43 were found to be insignificantly altered. Only the expression of M1 were significantly changed in high doses of adult group. Thus imidacloprid in high doses causes deterioration in cognitive functions particularly in infant rats, and this deterioration may be associated with changes in the expressions of related genes.

The spectrum of MEFV gene mutations and genotypes in Van province, the eastern region of Turkey, and report of a novel mutation (R361T)

Familial Mediterranean fever (FMF) is the most common hereditary inflammatory periodic disease, characterized by recurrent episodes of fever and abdominal pain, synovitis, and pleuritis. The aim of this study was to determine the frequency and distribution of Mediterranean fever (MEFV) gene mutations in Van province of Eastern Anatolia and to compare them with the other studies from various regions of Turkey. Therefore, we retrospectively evaluated MEFV gene mutations in 1058 pediatric patients with suspected FMF. The MEFV gene mutations were investigated using Sanger sequencing and the multiplex minisequencing technique. We identified 37 different genotypes and 16 different mutations. The four most common mutations and allelic frequencies were M694V (36.50%), E148Q (32.77%), V726A (14.09%), and M694I (4.41%). M694V was the most common mutation, and the M694I frequency was found to be higher compared to studies from other regions of Turkey. In addition, we identified a novel missense mutation (R361T, c.1082G>C) in exon 3 of the MEFV gene in a 12-year-old boy, who had a typical FMF phenotype. In conclusion, this study evaluated the distribution of MEFV gene mutations in children with FMF as the first study conducted in Van province, Eastern Anatolia.

Association of Polymorphisms within the Serotonin Receptor Genes 5-HTR1A, 5-HTR1B, 5-HTR2A and 5-HTR2C and Migraine Susceptibility in a Turkish Population

Objective Migraine, a highly prevelant headache disorder, is regarded as a polygenic multifactorial disease. Serotonin (5-HT) and their respective receptors have been implicated in the patogenesis. Methods We investigated the 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT2C receptor gene polymorphisms and their association with migraine in Turkish patients. The rs6295, rs1300060, rs1228814, rs6311, rs6313, rs6314, rs6318, rs3813929 (−759C/T) and rs518147 polymorphisms were analyzed in 135 patients with migraine and 139 healthy subjects, using a BioMark 96.96 dynamic array system. Results We found no difference in the frequency of the analyzed eight out of nine polymorpisms between migraine and control groups. However, a significant association was found between the rs3813929 polymorphism in the promoter region of 5-HTR2C gene and migraine. Also, the allele of rs3813929 was more common in the migraine group. Conclusion This result suggests that the 5-HTR2C rs3813929 polymorphism can be a genetic risk factor for migraine in a Turkish population.

Rhizomelic Chondrodysplasia Punctata Type 1 Caused by a Novel Mutation in the PEX7 Gene.

Peroxisomes are involved in various metabolic reactions. Rhizomelic chondrodysplasia punctata (RCDP) type 1 is one of the peroxisomal biogenesis disorders caused by mutations in the PEX7 gene and is inherited in an autosomal recessive manner. We present a nine-year-old boy with skeletal abnormalities and dysmorphic facial appearance. The patient was born to parents who were first cousins. Very-long-chain fatty acids and pristanic acid levels were in the normal range, but an elevated phytanic acid level was detected by gas chromatography/mass spectrometry. The PEX7 gene was sequenced in the patient and his parents. A novel homozygous mutation, c.192delT (p.F64Lfs*10), was identified in the patient and was present in heterozygosity in both parents. In conclusion, the clinical presentation and peroxisome profile of the patient suggest that this novel mutation leads to RCDP type 1.

Peripheral Signatures of Psychiatric Disorders: MicroRNAs

MicroRNAs (miRNAs) are 22 nucleotide long RNA transcripts, their synthesis starts in nucleus and continues in cytoplasm. As being critical for post-transcriptional regulators of gene expression they have been investigated in psychiatric disorders. There are numerous studies performed in peripheral tissues for psychiatric disorders. Here in this article, we aimed to review some common miRNAs denoted significant in at least two studies and their relevance to psychiatric research. We focused on miR-320, miR-106, miR-34, miR-223, miR-107, and miR-134.