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Warburg micro syndrome (WARBM) is a rare, autosomal recessive, neurodevelopmental disorder characterized by microcephaly, cortical dysplasia, corpus callosum hypoplasia, congenital hypotonia leading to subsequent spastic quadriplegia, severe developmental delay and hypogenitalism. Ophthalmologic findings that may affect any ocular segment including characteristic, small, atonic pupils. WARBM is known to be caused by biallelic, pathogenic variants in at least five genes although additional genetic loci may exist. The RAB3GAP1 c.748 + 1G>A, p.Asp250CysfsTer24 founder variant has been described in families of Turkish ancestry. We report the clinical and molecular findings in three, unrelated, Turkish families with WARBM. A novel c.974-2A>G variant causing WARBM in three siblings of Turkish descent was found. Functional studies of the novel, c.2606 + 1G>A variant in patients\" mRNA revealed skipping of exon 22 which results in a premature stop codon in exon 23. However, the clinical consequences of this variant are blended given that the individual also had a maternally inherited chromosome 3q29 microduplication.

Introduction: Grange syndrome (OMIM 602531) is characterized by a constellation of symptoms of hypertension, stenosis, or occlusion of different arteries (including the cerebral, renal, abdominal, and coronary vessels) with a variable occurrence of brachysyndactyly, bone fragility, and congenital heart defects. Learning disabilities were also reported in some cases. Biallelic pathogenic variants in YY1AP1 are associated with the syndrome. Only 14 individuals with this ultra-rare syndrome (12 of them were molecularly confirmed) have hitherto been reported in the literature. Case Presentation: We herein describe a 11/2-year-old additional female case of Grange syndrome with hypertension, patent ductus arteriosus, and brachysyndactyly who was subsequently confirmed to carry a novel homozygous frameshift variant (c.2291del; p.Pro764Leufs*12) in the YY1AP1 gene through whole-exome sequencing. Conclusion: This report extends the allelic spectrum in Grange syndrome and helps provide insight into the potential role of YY1AP1 in the regulation of cellular processes.

Charcot-Marie-Tooth (CMT) disease represents a distinct subgroup of inherited peripheral neuropathies with a significant prevalence throughout the world and manifests both phenotypic and genetic heterogeneity. Electrophysiological studies subclassify CMT mainly as demyelinating or axonal types. In this study, we investigated the molecular characteristics of a Turkish cohort of 23 probands out of 34 symptomatic demyelinating CMT individuals from January 2019 to December 2021. In order to identify the underlying genetic cause, we applied a rational algorithm: PMP22 gene was initially analyzed for duplication, if PMP22-duplication testing was negative, other most causative genes (GJB1, MPZ) and PMP22 were then sequenced and if no variant was detected at aforementioned tests, whole exome sequencing (WES) test was finally performed. A total of 17 patients (≅ 74%; n = 23) were found to harbor a disease-causing variant in demyelinating CMT-related genes and among the variants, PMP22-duplication was the most frequent (≅ 41%). CMT1, CMTX, and CMT4 subtypes were manifested in ten, five, and two individuals respectively. GJB1 and SBF2 genes were the only detected genes associated with the CMTs other than CMT1. We also reported totally five novel variants: c.379A C (p.Ile127Leu) and c.548G T (p.Arg183Leu) variants in GJB1, c.988G T (p.Glu330Ter) variant in NEFL, c.765_770delCCCTAT (p.Pro256_Ile257del) and c.2552A C (p.His851Pro) variants in SBF2. As the understanding of pathophysiology and molecular mechanisms of CMT continues to evolve rapidly, many therapeutic strategy options including promising small-molecular compounds, gene replacement therapy, or disease-modifying therapies will soon be implemented in the clinical setting.

PURPOSE: Premature ovarian insufficiency (POI) is a heterogeneous disorder characterized by the cessation of menstrual cycles before the age of 40 years due to the depletion or dysfunction of the ovarian follicles. POI is a highly heterogeneous disease in terms of etiology. The aim of this study is to reveal the genetic etiology in POI patients. METHODS: A total of 35 patients (mean age: 27.2 years) from 28 different families diagnosed with POI were included in the study. Karyotype, FMR1 premutation analysis, single nucleotide polymorphism (SNP) array, and whole-exome sequencing (WES) were conducted to determine the genetic etiology of patients. RESULTS: A total of 35 patients with POI were first evaluated by karyotype analysis, and chromosomal anomaly was detected in three (8.5%) and FMR1 premutation was detected in six patients (17%) from two different families. A total of 29 patients without FMR1 premutation were included in the SNP array analysis, and one patient had a 337-kb deletion in the chromosome 6q26 region including PARK2 gene, which was thought to be associated with POI. Twenty-nine cases included in SNP array analysis were evaluated simultaneously with WES analysis, and genetic variant was detected in 55.1% (16/29). CONCLUSION: In the present study, rare novel variants were identified in genes known to be associated with POI, which contribute to the mutation spectrum. The effects of detected novel genes and variations on different pathways such as gonadal development, meiosis and DNA repair, or metabolism need to be investigated by experimental studies. Molecular etiology allows accurate genetic counseling to the patient and family as well as fertility planning.

Background: Beck-Fahrner syndrome is caused by homozygous or heterozygous mutations in TET3 on chromosome 2p13. The general characteristics of this syndrome include behavioral abnormalities such as autistic features, attention-deficit hyperactivity disorder, learning disabilities, and epilepsy. Case presentation: Six years old male patient was found to have a de novo TET3 loss-of-function variant by whole-exome sequencing (WES) analysis and was diagnosed with electrical status epilepticus during slow-wave sleep (ESES) based on clinical and electroencephalogram (EEG) characteristics. The patient had a neurodevelopmental delay from the age of 3 months and started experiencing generalized tonic-clonic seizures and regression at the age of 5 years. EEG findings were consistent with ESES, and WES analysis revealed a novel heterozygous nonsense NM_001366022.1:c.1594C > T (p.Arg532*) variant in TET3. Valproic acid and immunotherapy were administered for the first 6 months, and clobazam was administered orally in addition to oral valproic acid therapy for the next 6 months. Clinical improvement was noted regardless of EEG improvement for the first 6 months. EEG improvement was achieved with clobazam. No regression was observed following the discontinuation of immunotherapy. Conclusion: Decreased TET3 enzyme activity may be one of the new genetic etiologies of ESES. Keywords: Electrical status epilepticus during slow-wave sleep; Epilepsy; Status epilepticus; TET3 gene; Treatment.

@ 2022 by the Istanbul Medeniyet University.Objective: Hereditary cancer syndromes (HCSs) are a heterogenous group of disorders caused by germline pathogenic variations in various genes that function in cell growth and proliferation. This study aimed to describe the germline variations in patients with hereditary cancer using multigene panels. Methods: The molecular and clinical findings of 218 patients with HCS were evaluated. In addition, 25 HCS-related genes were sequenced using a multigene panel, and variations were classified according to the American College of Medical Genetics and Genomics (ACMG) criteria. In total, 218 HCS patients predominantly with breast, colorectal, ovarian, gastric, and endometrium cancers were included. Results: Pathogenic variations in 12 distinct genes were detected in 36 of 218 (16.5%) cases. In this study, the most affected gene was the ATM gene, in which pathogenic variations were detected in 8 of 218 cases, followed by CHEK2 (3.2%), MUTYH (3.2%), BRIP1 (1.8%), BARD1 (0.9%), TP53 (0.9%), PALB2 (0.4%), MLH1 (0.4%), MSH2 (0.4%), PMS2 (0.4%), RAD50 (0.4%), and RAD51C (0.4%). Conclusions: This study contributes to genotype-phenotype correlation in HCSs and expands the variation spectrum by introducing three novel pathogenic variations. The wide spectrum of the gene pathogenic variations detected and the presence of multiple gene defects in the same patient make the multigene panel testing a valuable tool in detecting the hereditary forms of cancer and providing effective genetic counseling and family specific screening strategies. Amaç: Herediter kanser sendromları (HCS) hücre büyümesi ve proliferasyonunda görevli genlerde saptanan germline mutasyonlardan kaynaklanan heterojen bir grup hastalıktır. Bu çalışmada kalıtımsal kanser sendrom ön tanısıyla değerlendirilen olgularda çoklu gen paneli ile germ hattı varyasyonlarının değerlendirilmesi planlanmıştır. Yöntemler: Kalıtımsal kanser sendromu düşünülen 218 olgudan periferik kandan DNA izolasyonu sonrası HCS ile ilişkili 25 gen multigen panel kullanılarak dizilendi ve varyasyonlar American College of Medical Genetics and Genomics (ACMG) kriterlerine göre değerlendirildi. Bulgular: Meme, kolorektal, over, gastrik ve endometriyum kanseri başta olmak üzere toplam 218 herediter kanser sendromlu olgu değerlendirildi. Tüm çalışma grubu incelendiğinde en sık ATM gen varyasyonları (8/218, %3,6) tespit edildi ve bunu sıklık sırasına göre CHEK2 (%3,2), MUTYH (%3,2), BRIP1 (%1,8), BARD1 (%0,9), TP53 (%0,9), PALB2 (%0,4), MLH1 (%0,4), MSH2 (%0,4), PMS2 (%0,4), RAD50 (%0,4), RAD51C (%0,4) varyasyonları takip etmekteydi. Sonuçlar: Bu çalışmada farklı kanser türlerinde kalıtımsal kansere yol açan genler analiz edilmiş ve fenotiple ilişkisi değerlendirilmiştir. Ayrıca bu çalışmada ilk kez saptanan üç yeni varyasyon ile literatüre katkı sağlanmaktadır. Patojenik varyasyon tespit edilen genlerin geniş dağılımı ve aynı hastada birden fazla genetik varyasyonun varlığı düşünüldüğünde, uygun genetik danışma ve aileye özgü tarama planlaması yapmak için çoklu gen taraması kalıtımsal kanser hastalarının değerlendirilmesinde hızlı ve etkin bir yöntem olarak görünmektedir.