Search

Background: Idiopathic generalized epilepsy is the most common group of epilepsy disorders in children and adolescents. Various types of genetic abnormality were identified among the hereditary factors that explain epilepsy., Aims: To determine the variations in the etiopathogenesis, treatment protocol planning, and prognosis of idiopathic generalized epilepsy using the next-generation sequencing method., Study Design: A cross-sectional study., Methods: This study included 32 patients with idiopathic generalized epilepsy. Genomic DNA was obtained from peripheral venous blood samples taken from the patients. A total of 18 genes encoding ion channel subunits that are involved in monogenic disorders and are associated with idiopathic generalized epilepsy were included. The targeted custom next-generation sequencing panel was designed to cover all coding exons and all exon/intron splice site regions of 18 genes., Results: We detected 9 (28%) variations, including 1 likely pathogenic (a variant in the SCN1A gene) and 8 of unknown clinical significance (2 in the CLCN2 genes, GABBR2, SCN1B, SLC2A1, SLC4A10 genes, and 2 in the TBC1D24 gene)., Conclusion: Study results should be supported by functional advanced studies, with increased existing knowledge in the relevant variations.

Background: Tuberous Sclerosis Complex is an autosomal dominant multi-system disorder with an incidence of about 1 in 6000 live births. Defects in either TSC1 (* 605284) or TSC2 (* 191092) genes encoding the components of the Tuberous Sclerosis Complex are responsible for the disease. Therefore, consideration of TSC1/TSC2 pathogenic variations is recommended in the updated diagnostic criteria of Tuberous Sclerosis Complex., Aims: To present the TSC1/TSC2 screening results of a mixed patient population as well as possible new variants in 23 cases from 20 different families who were referred to our Genetic Diseases Diagnosis Center with the signs and symptoms of Tuberous Sclerosis Complex., Study Design: Retrospective, cross-sectional study., Methods: Germline TSC1/TSC2 variants were screened in DNA samples extracted from peripheral blood samples of 23 patients from 20 unrelated families using targeted high-throughput sequencing and multiplex ligation-dependent probe amplification methods. The variants identified were classified according to ACMG 2015 guidelines., Results: In total, 5 different pathogenic/likely pathogenic changes have been defined. All these pathogenic/likely pathogenic variants were located in the TSC2 gene. Three of the pathogenic/likely pathogenic variants were novel. Two patients who are twin sisters were found to have TSC2/PKD1 contiguous deletion syndrome. One of the 3 novel variants was a mosaic in-frame deletion. We did not identify any pathogenic variants of the TSC1 gene., Conclusion: The novelty of most of the variants found, including a mosaic likely pathogenic variant, and the presence of a large genomic rearrangement, supports the importance of a comprehensive approach in analyzing TSC1/TSC2 genes. Genetic diagnosis should be performed with caution, considering the possibility of mosaic variants with low allelic fractions.

Aims: Hereditary hemorrhagic telangiectasia is an autosomal dominant disorder characterized by telangiectasia, epistaxis, and vascular malformations. Pathogenic mutations were found in ENG, AVCRL1, SMAD4 , and GDF genes. In this study, we present our database of patients with hereditary hemorrhagic telangiectasia regarding the phenotype-genotype relations and discuss two novel ENG gene pathogenic variations in two unrelated families., Methods: Next Generation Sequencing analysis was performed on the peripheral blood of nine patients with hereditary hemorrhagic telangiectasia in four unrelated families. All patients were diagnosed with hereditary hemorrhagic telangiectasia according to the Curaçao criteria. Data on treatment and screenings of visceral involvement were recorded from files., Results: We have found a pathogenic variation in either the ENG or ACVRL1 gene in each family. Two novel pathogenic variations in the ENG gene, including NM_000118.3 (ENG): c.416delC (p.P139fs*24) and NM_000118.3(ENG): c.1139dupT (p.Leu380PhefsTer16), were found in the same family. The NM_000020.2(ACVRL1): c.1298C>T (p.Pro433Leu) pathogenic variation in the ACVRL1 gene in our first family and a novel heterozygous likely pathogenic NM_000020.2(ACVRL1): c.95T>C (p.Val32Ala) variation was found in our second family. Seven of the nine patients were treated with thalidomide for controlling bleeding episodes. All patients responded to thalidomide. In one patient, the response to thalidomide was lost and switched to bevacizumab., Conclusion: In HHT certain type of mutations correlates with disease phenotypes and with next generation sequencing method, new pathogenic variations can be revealed which might help managing HHT patients.

Background: Atopic dermatitis is the most common chronic inflammatory skin disease. A complex interaction of both genetic and environmental factors is thought to contribute to the disease., Aims: To evaluate whether single nucleotide polymorphisms in the TLR2 gene c.2258C>T (R753Q) (rs5743708) and TLR2 c.-148+1614T>A (A-16934T) (rs4696480) (NM_0032643) are associated with atopic dermatitis in Turkish children., Study Design: Case-control study., Methods: The study was conducted on 70 Turkish children with atopic dermatitis aged 0.5-18 years. The clinical severity of atopic dermatitis was evaluated by the severity scoring of atopic dermatitis index. Serum total IgE levels, specific IgE antibodies to inhalant and food allergens were measured in both atopic dermatitis patients and controls, skin prick tests were done on 70 children with atopic dermatitis. Genotyping for TLR2 (R753Q and A-16934T) single nucleotide polymorphisms was performed in both atopic dermatitis patients and controls., Results: Cytosine-cytosine and cytosin-thymine genotype frequencies of the TLR2 R753Q single nucleotide polymorphism in the atopic dermatitis group were determined as being 98.6% and 1.4%, cytosine allele frequency for TLR2 R753Q single nucleotide polymorphism was determined as 99.29% and the thymine allele frequency was 0.71%, thymine-thymine, thymine-adenine, and adenine-adenine genotype frequencies of the TLR2 A-16934T single nucleotide polymorphism were 24.3%, 44.3%, and 31.4%. The thymine allele frequency for the TLR2 A-16934T single nucleotide polymorphism in the atopic dermatitis group was 46.43%, and the adenine allele frequency was 53.57%, respectively. There was not statistically significant difference between the groups for all investigated polymorphisms (p>0.05). For all single nucleotide polymorphisms studied, allelic distribution was analogous among atopic dermatitis patients and controls, and no significant statistical difference was observed. No homozygous carriers of the TLR2 R753Q single nucleotide polymorphism were found in the atopic dermatitis and control groups., Conclusion: The TLR2 (R753Q and A-16934T) single nucleotide polymorphisms are not associated with atopic dermatitis in a group of Turkish patients.

Background: Lung cancer is one of the most lethal cancers. It is mainly classified into 2 groups: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Extrapulmonary small cell carcinomas (EPSCC) are very rare. The Ras oncogene controls most of the cellular functions in the cell. Overall, 21.6% of human cancers contain a Kirsten Ras (KRAS) mutation. SCLC and EPSCC have several similar features but their clinical course is different., Aims: We investigated the KRAS mutation status in SCLC and EPSCC., Study Design: Mutation research., Methods: Thirty-seven SCLC and 15 EPSCC patients were included in the study. The pathological diagnoses were confirmed by a second pathologist. KRAS analysis was performed in our medical genetic department. DNA isolation was performed with primary tumor tissue using the QIAamp DNA FFPE Tissue kit (Qiagen; Hilden, Germany) in all patients. The therascreen KRAS Pyro Kit 24 V1 (Qiagen; Hilden, Germany) was used for KRAS analyses., Results: Thirty-four (91.9%) of the SCLC patients were male, while 11 (73.3%) of the EPSCC l patients were female. SCLC was more common in males, and EPSCC in females (p=0.001). A KRAS mutation was found in 6 (16.2%) if SCLC patients. The most common mutation was Q61R (CAA>CGA). Among the 15 EPSCC patients, 2 had a KRAS mutation (13.3%). When KRAS mutant and wild type patients were compared in the SCLC group, no difference was found for overall survival (p=0.6)., Conclusion: In previous studies, the incidence of KRAS mutation in SCLC was 1-3%; however, it was 16.2% in our study. Therefore, there may be ethnic and geographical differences in the KRAS mutations of SCLC. As a result, KRAS mutation should not be excluded in SCLC.

Objective: To investigate possible mitochondrial DNA (mtDNA) mutations in patients with Leber's hereditary optic neuropathy (LHON) in order to provide a precise diagnosis and genetic counseling., Material and Methods: Between 1982 and 2007, ten patients were clinically diagnosed with LHON and six of these patients agreed to be involved in this study. Six healthy individuals were also included as a control group. mtDNA was isolated from peripheral blood samples and polymerase chain reaction and mtDNA sequence analysis were performed., Results: In one of the six patients, a homoplasmic mutant m.11778G>A mutation was detected. All of the clinically diagnosed LHON patients and the control groups had the m.14212C>T and m.14580G>A single nucleotide polymorphisms (SNPs). The m.11719A>G SNP was detected in three of six patients and four of the controls. Two of the six patients had the m.3197T>C SNP and, in addition, the m.14258G>A SNP was found in one of these two patients, while neither of these mutations were present in the control group., Conclusion: The clinical diagnosis of LHON could be supported by molecular genetics only in one patient by the detection of one mutation. The m.3197T>C and m.14258G>A SNPs should be considered as potential mtDNA mutations due to the fact that they were detected in the patient group. These mutations should be investigated further in large case groups for suspected gene loci that could lead to optic neuropathy.