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The balanced non-Robertsonian translocation (ROB) associated with acrocentric chromosomes is an unusual phenomenon. We report the case of rare non-ROB involving chromosomes 15 and 22 with cytogenetic and molecular cytogenetic findings of 46,XY,t(15;22)(p11.2;q11.2). To the best of our knowledge, t(15;22) is the first report of this breakpoint that is not the usual non-ROB. The karyotype of the chorionic villus cell was 46,XY,t(15;22)(p11.2; q11.2) from two different initial cultures. This is different from the usual non-ROB of acrocentric chromosomes. Comparative genomic hybridization has been performed to determine the chromosomal origin. Non-Robertsonian translocation associated with acrocentric chromosomes is an unusual event and only a few cases have been reported. In this study, we observed acrocentric chromosomes 15 and 22 as a rarely balanced non-ROB, where satellites of chromosome 15 translocated to chromosome 22 and part of chromosome 22 were translocated to chromosome 15. To the best of our knowledge, our patient is the first case reported in the literature for this translocation in prenatal and postnatal periods.

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.

Introduction: Germline pathogenic variations of the genes encoding the components of the Ras-MAPK pathway are found to be responsible for RASopathies, a clinically and genetically heterogeneous group of diseases. In this study, we aimed to present the results of patients genetically investigated for RASopathy-related mutations in our Genetic Diagnosis Center., Methods: The results of 51 unrelated probands with RASopathy and 4 affected relatives (31 male, 24 female; mean age: 9.327 ± 8.214) were included in this study. Mutation screening was performed on DNA samples from peripheral blood of the patients either by Sanger sequencing of PTPN11 hotspot regions (10/51 probands), or by a targeted amplicon next-generation sequencing panel (41/51 probands) covering the exonic regions of BRAF, CBL, HRAS, KRAS, LZTR1, MAP2K1, MAP2K2, NF1, NRAS, PTPN11, RAF1, RASA2, RIT1, SHOC2, SOS1, SOS2, SPRED1 , and KAT6B genes., Results: Pathogenic/likely pathogenic variations found in 22 out of 51 probands (43.13%) and their 4 affected family members were located in PTPN11, BRAF, KRAS, NF1, RAF1, SOS1 , and SHOC2 genes. The c.148A>C (p.Thr50Pro) variation in the KRAS gene was a novel variant detected in a sibling in our patient cohort. We found supportive evidence for the pathogenicity of the NF1 gene c.5606G>T (p.Gly1869Val) variation which we defined in an affected boy who inherited the mutation from his affected father., Conclusion: Although PTPN11 is the most frequently mutated gene in our patient cohort, as in most previous reports, different mutation distribution among the other genes studied motivates the use of a next-generation sequencing gene panel including the possible responsible genes., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2022 by S. Karger AG, Basel.)

Objective: The aim of this study was to investigate the molecular basis of maturity-onset diabetes of the young (MODY) by targeted-gene sequencing of 20 genes related to monogenic diabetes, estimate the frequency and describe the clinical characteristics of monogenic diabetes and MODY in the Trakya Region of Turkey., Methods: A panel of 20 monogenic diabetes related genes were screened in 61 cases. Illumina NextSeq550 system was used for sequencing. Pathogenicity of the variants were assessed by bioinformatics prediction software programs and segregation analyses., Results: In 29 (47.5%) cases, 31 pathogenic/likely pathogenic variants in the GCK, ABCC8, KCNJ11, HNF1A, HNF4A genes and in 11 (18%) cases, 14 variants of uncertain significance (VUS) in the GCK, RFX6, CEL, PDX1, KCNJ11, HNF1A, G6PC2, GLIS3 and KLF11 genes were identified. There were six different pathogenic/likely pathogenic variants and six different VUS which were novel., Conclusion: This is the first study including molecular studies of twenty monogenic diabetes genes in Turkish cases in the Trakya Region. The results showed that pathogenic variants in the GCK gene are the leading cause of MODY in our population. A high frequency of novel variants (32.4%-12/37) in the current study, suggests that multiple gene analysis provides accurate genetic diagnosis in MODY.

Objective: Osteogenesis imperfecta (OI) includes a group of disorders characterized by susceptibility to bone fractures with different severities. The increasing number of genes that may underlie the disorder, along with the broad phenotypic spectrum that overlaps with other skeletal diseases, provided a compelling case for the use of high-throughput sequencing (HTS) technology as an aid to OI diagnoses. The aim of this analysis was to present the data from our 5-year targeted HTS results, that includes the reporting of 9 novel and 24 known mutations, found in OI patients, from 5 different regions of Turkey. Materials and Methods: We performed a retrospective cross-sectional study, reporting the HTS results of 43 patients (23 female and 20 male; mean age: 9.5 years), directed to our center with a suspicion of OI between February 2015 and May 2020. Genetic analyses were also performed for 24 asymptomatic parents to aid the segregation analyses. We utilized an HTS panel targeting the coding regions of 57 genes associated with a reduction, increase, or abnormal development of bone mineralization. In addition, we sequenced the entire coding region of the IFITM5 gene through HTS. Results: Thirty-nine patients had at least one pathogenic/likely pathogenic variation (90.69%) in the COL1A1 (56.41%), COL1A2 (20.51%), FKBP10 (7.7%), P3H1 (5.13%), IFITM 5 (5.13%), CTRAP (2.56%), or TMEM38B (2.56%) genes. Nine of the determined pathogenic/likely pathogenic variations were novel. The recurrent pathogenic mutations were c.1081C>T (p.Arg361Ter) (3/43), c.1405C>T (p.Arg469Ter) (2/43), and c.3749del (p.Gly1250AlafsTer81) in COL1A1 gene, along with c.-14C>T variation in the 5'UTR of the IFITM5 gene (2/43) and the c.890_897dup variation in the FKBP10 gene (2/43). Three out of 43 patients were carrying at least one additional variant of unknown significance, highlighting the importance of a multigene panel approach and segregation analyses. Conclusion: We suggest that a targeted HTS panel is a feasible tool for genetic diagnosis of OI in patients.