Person: GEÇKİNLİ, BİLGEN BİLGE
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
GEÇKİNLİ
First Name
BİLGEN BİLGE
Name
7 results
Search Results
Now showing 1 - 7 of 7
Publication Metadata only Bi-allelic TTI1 variants cause an autosomal-recessive neurodevelopmental disorder with microcephaly(2023-03-01) GEÇKİNLİ, BİLGEN BİLGE; Serey-Gaut M., Cortes M., Makrythanasis P., Suri M., Taylor A. M. R., Sullivan J. A., Asleh A. N., Mitra J., Dar M. A., McNamara A., et al.Telomere maintenance 2 (TELO2), Tel2 interacting protein 2 (TTI2), and Tel2 interacting protein 1 (TTI1) are the three components of the conserved Triple T (TTT) complex that modulates activity of phosphatidylinositol 3-kinase-related protein kinases (PIKKs), including mTOR, ATM, and ATR, by regulating the assembly of mTOR complex 1 (mTORC1). The TTT complex is essential for the expression, maturation, and stability of ATM and ATR in response to DNA damage. TELO2- and TTI2-related bi-allelic autosomal-recessive (AR) en-cephalopathies have been described in individuals with moderate to severe intellectual disability (ID), short stature, postnatal micro-cephaly, and a movement disorder (in the case of variants within TELO2). We present clinical, genomic, and functional data from 11 individuals in 9 unrelated families with bi-allelic variants in TTI1. All present with ID, and most with microcephaly, short stature, and a movement disorder. Functional studies performed in HEK293T cell lines and fibroblasts and lymphoblastoid cells derived from 4 unrelated individuals showed impairment of the TTT complex and of mTOR pathway activity which is improved by treatment with Rapamycin. Our data delineate a TTI1-related neurodevelopmental disorder and expand the group of disorders related to the TTT complex.Publication Metadata only Enostosis in a patient with KBG syndrome caused by a novel missense ANKRD11 variant(2022-07-01) GEÇKİNLİ, BİLGEN BİLGE; ALAVANDA, CEREN; ARMAN, AHMET; GEÇKİNLİ B. B., ALAVANDA C., Ates E. A., Yildirim O., ARMAN A.KBG syndrome (KBGS-OMIM:#148050) is a rare autosomal dominant disease characterized by short stature, intellectual disability, characteristic facies, skeletal anomalies and macrodontia that most commonly affect the permanent upper central incisors. In 2011, Sirmaci et al. (2011) identified heterozygous loss-of-function variants in the ANKRD11 gene on chromosome 16q24.3. So far, more than 150 patients have been reported in the literature. ANKRD11 gene encodes ankyrin repeat domain-containing protein 11 that regulates transcriptional activation (Zhang et al., 2004). Apart from single-nucleotide variations in the ANKRD11 gene, copy number variations on chromosome 16q24.3 can also cause KBG syndrome-like phenotype. In this study, we present a patient with de-novo novel missense variant in ANKRD11 gene. We have also identified skeletal bone enostosis as an additional finding, which is not previously reported.Publication Open Access Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium(2022-06-01) ARMAN, AHMET; GEÇKİNLİ, BİLGEN BİLGE; DÜNDAR M., FAHRİOGLU U., Yildiz S. H., Bakir-Gungor B., TEMEL Ş. G., AKIN H., ARTAN S., Cora T., ŞAHİN F. İ., DURSUN A., et al.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.Publication Metadata only FGF3 related phenotypes : A study of lamm syndrome and otodental dysplasia patients with two novel mutations in FGF3 genee(2020-08-01) GEÇKİNLİ, BİLGEN BİLGE; ALAVANDA, CEREN; ARMAN, AHMET; TÜRKYILMAZ A., GEÇKİNLİ B. B., ALAVANDA C., ZENGİN G., ARSLAN ATEŞ E., ARMAN A.The fibroblast growth factor (FGF) signaling pathway regulates the intracellular events which are involved in the proper formation of the internal organs and limbs during the earliest stages of embryonic development. Here, the researchers performed a detailed examination of clinical and radiological findings from syndromic cases with sensorineural hearing loss and determined their molecular genetic etiology. Family history, physical examination, laboratory and radiological examinations for three Turkish families displaying congenital sensorineural hearing loss, microtia, dental anomalies and neuromotor developmental delay were evaluated and molecular analysis of the FGF3 gene was performed. The researchers detected a heterozygous deletion of a 2.4 Megabase (Mb) segment in the region spanning 68,734,891 to 71,538,481 bases in the chromosome 11q13.3-q13.4. Interestingly, this region included the FGF3 gene in case 1, whereas two novel mutations (NM_005247: c.8T>G, p.Leu3Arg, NM_005247: c.324+2T>C) were identified in case 2 and case 3 respectively. From this study, the researchers conclude that in the absence of inner ear structures in cases of syndromic hearing loss, FGF3 gene related phenotypes should be considered and the FGF3 gene should be examined by sequence analysis and array-CGH methods for both point mutations and gross deletions.Publication Open Access Two new cases with novel pathogenic variants reflecting the clinical diversity of Schaaf-Yang syndrome(2023-01-01) ALAVANDA, CEREN; GEÇKİNLİ, BİLGEN BİLGE; DEMİRCİOĞLU, SERAP; ARMAN, AHMET; ALAVANDA C., Arslan Ateş E., Yavaş Abalı Z., GEÇKİNLİ B. B., DEMİRCİOĞLU S., ARMAN A.Schaaf-Yang syndrome (SHFYNG) is a rare pleiotropic disorder, characterized by hypotonia, joint contractures, autism spectrum disorders (ASD), and developmental delay/intellectual disability. Although it shares some common features with Prader-Willi Syndrome, joint contractures, and ASD were more commonly detected in in this syndrome. Recently, it was shown that truncating variants in the paternal allele of the MAGEL2 gene cause SHFYNG. Here, we present two patients diagnosed with SHFYNG syndrome having two different novel truncating variants in the MAGEL2 gene, one paternally inherited and one de novo. One patient had obesity, brachydactyly and dysmorphic features, and the other patient presented with contractures, severe hypotonia and early death. This is the first report of Turkish SHFYNG syndrome cases presented to emphasize the phenotypic diversity of the syndrome.Publication Metadata only Biallelic TTI1 pathogenic variants cause a microcephalic neurodevelopmental disorder(2022-04-01) GEÇKİNLİ, BİLGEN BİLGE; Serey-Gaut M., Essien-Umanah G. K., Makrythanasis P., Suri M., Taylor A. M., Sullivan J., Shashi V., Song X., Rosenfeld J. A., Cabrol C., et al.Publication Metadata only Biallelic variants in HECT E3 paralogs, HECTD4 and UBE3C, encoding ubiquitin ligases cause neurodevelopmental disorders that overlap with Angelman syndrome(2022-01-01) GEÇKİNLİ, BİLGEN BİLGE; Faqeih E. A. , Alghamdi M. A. , Almahroos M. A. , Alharby E., Almuntashri M., Alshangiti A. M. , Clément P., Calame D. G. , Qebibo L., Burglen L., et al.© 2022 American College of Medical Genetics and GenomicsPurpose: Pathogenic variants in genes encoding ubiquitin E3 ligases are known to cause neurodevelopmental syndromes. Additional neurodevelopmental disorders associated with the other genes encoding E3 ligases are yet to be identified. Methods: Chromosomal analysis and exome sequencing were used to identify the genetic causes in 10 patients from 7 unrelated families with syndromic neurodevelopmental, seizure, and movement disorders and neurobehavioral phenotypes. Results: In total, 4 patients were found to have 3 different homozygous loss-of-function (LoF) variants, and 3 patients had 4 compound heterozygous missense variants in the candidate E3 ligase gene, HECTD4, that were rare, absent from controls as homozygous, and predicted to be deleterious in silico. In 3 patients from 2 families with Angelman-like syndrome, paralog-directed candidate gene approach detected 2 LoF variants in the other candidate E3 ligase gene, UBE3C, a paralog of the Angelman syndrome E3 ligase gene, UBE3A. The RNA studies in 4 patients with LoF variants in HECTD4 and UBE3C provided evidence for the LoF effect. Conclusion: HECTD4 and UBE3C are novel biallelic rare disease genes, expand the association of the other HECT E3 ligase group with neurodevelopmental syndromes, and could explain some of the missing heritability in patients with a suggestive clinical diagnosis of Angelman syndrome.