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He D, Zhang M, Li Y, Liu F, Ban B. Insights into the ANKRD11 variants and short-stature phenotype through literature review and ClinVar database search. Orphanet J Rare Dis 2024; 19:292. [PMID: 39135054 PMCID: PMC11318275 DOI: 10.1186/s13023-024-03301-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 08/05/2024] [Indexed: 08/16/2024] Open
Abstract
Ankyrin repeat domain containing-protein 11 (ANKRD11), a transcriptional factor predominantly localized in the cell nucleus, plays a crucial role in the expression regulation of key genes by recruiting chromatin remodelers and interacting with specific transcriptional repressors or activators during numerous biological processes. Its pathogenic variants are strongly linked to the pathogenesis and progression of multisystem disorder known as KBG syndrome. With the widespread application of high-throughput DNA sequencing technologies in clinical medicine, numerous pathogenic variants in the ANKRD11 gene have been reported. Patients with KBG syndrome usually exhibit a broad phenotypic spectrum with a variable degree of severity, even if having identical variants. In addition to distinctive dental, craniofacial and neurodevelopmental abnormalities, patients often present with skeletal anomalies, particularly postnatal short stature. The relationship between ANKRD11 variants and short stature is not well-understood, with limited knowledge regarding its occurrence rate or underlying biological mechanism involved. This review aims to provide an updated analysis of the molecular spectrum associated with ANKRD11 variants, investigate the prevalence of the short stature among patients harboring these variants, evaluate the efficacy of recombinant human growth hormone in treating children with short stature and ANKRD11 variants, and explore the biological mechanisms underlying short stature from both scientific and clinical perspectives. Our investigation indicated that frameshift and nonsense were the most frequent types in 583 pathogenic or likely pathogenic variants identified in the ANKRD11 gene. Among the 245 KBGS patients with height data, approximately 50% displayed short stature. Most patients showed a positive response to rhGH therapy, although the number of patients receiving treatment was limited. ANKRD11 deficiency potentially disrupts longitudinal bone growth by affecting the orderly differentiation of growth plate chondrocytes. Our review offers crucial insights into the association between ANKRD11 variants and short stature and provides valuable guidance for precise clinical diagnosis and treatment of patients with KBG syndrome.
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Affiliation(s)
- Dongye He
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272029, China.
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, China.
| | - Mei Zhang
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272029, China
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, China
| | - Yanying Li
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272029, China
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, China
| | - Fupeng Liu
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272029, China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, China
| | - Bo Ban
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272029, China.
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, China.
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, China.
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2
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Wei S, Li Y, Yang W, Chen S, Liu F, Zhang M, Ban B, He D. Functional investigation of a novel ANKRD11 frameshift variant identified in a Chinese family with KBG syndrome. Heliyon 2024; 10:e28082. [PMID: 38515699 PMCID: PMC10956060 DOI: 10.1016/j.heliyon.2024.e28082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/23/2024] Open
Abstract
KBG syndrome is a rare autosomal dominant condition characterized by multisystem developmental disorder, primarily caused by loss-of-function variants in ankyrin repeat domain-containing protein 11 (ANKRD11). Approximately 80 % of ANKRD11 variants associated with KBG syndrome, are frameshift and nonsense variants. Current insight into the pathogenesis of KBG syndrome resulting from ANKRD11 truncating variants remains limited. Here, we presented two members from a non-consanguineous Chinese pedigree both exhibiting characteristics fitting the KBG syndrome-associated phenotypic spectrum. Whole-exome sequencing identified a novel heterozygous frameshift variant in ANKRD11 (NM_013275.6, c.2280_2281delGT, p.Y761Qfs*20) in the proband. Sanger sequencing confirmed that the variant was inherited from her mother and co-segregated with KBG syndrome phenotype. In vitro functional assays revealed that the frameshift variant escaped nonsense-mediated mRNA decay, and resulting in a truncated protein with significantly increased expression levels compared to full-length ANKRD11. Immunofluorescence results demonstrated that truncated protein was predominantly expressed in the nucleus of HEK293 cells, while wild-type ANKRD11 was equally distributed in both the nucleus and cytoplasm. Moreover, the truncated protein significantly reduced CDKN1A/P21-promoter luciferase activity in comparison to wild-type ANKRD11 protein, as well as a remarkably decrease in the endogenous CDKN1A/P21 mRNA level in HEK293 cells. These findings suggest a loss of transcriptional activation function and potentially a dominant-negative mechanism. Overall, our study expands the mutational spectrum of ANKRD11 gene and provides new insights into the pathogenic mechanism of KBG syndrome caused by ANKRD11 truncating variants.
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Affiliation(s)
- Shuoshuo Wei
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, PR China
| | - Yanying Li
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, PR China
| | - Wanling Yang
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, PR China
| | - Shuxiong Chen
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, PR China
| | - Fupeng Liu
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, PR China
| | - Mei Zhang
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, PR China
| | - Bo Ban
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, PR China
- Chinese Research Center for Behavior Medicine in Growth and Development, Jining, PR China
| | - Dongye He
- Department of Endocrinology, Genetics and Metabolism, Affiliated Hospital of Jining Medical University, Jining, PR China
- Medical Research Center, Affiliated Hospital of Jining Medical University, Jining, PR China
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4
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Peluso F, Caraffi SG, Contrò G, Valeri L, Napoli M, Carboni G, Seth A, Zuntini R, Coccia E, Astrea G, Bisgaard AM, Ivanovski I, Maitz S, Brischoux-Boucher E, Carter MT, Dentici ML, Devriendt K, Bellini M, Digilio MC, Doja A, Dyment DA, Farholt S, Ferreira CR, Wolfe LA, Gahl WA, Gnazzo M, Goel H, Grønborg SW, Hammer T, Iughetti L, Kleefstra T, Koolen DA, Lepri FR, Lemire G, Louro P, McCullagh G, Madeo SF, Milone A, Milone R, Nielsen JEK, Novelli A, Ockeloen CW, Pascarella R, Pippucci T, Ricca I, Robertson SP, Sawyer S, Falkenberg Smeland M, Stegmann S, Stumpel CT, Goel A, Taylor JM, Barbuti D, Soresina A, Bedeschi MF, Battini R, Cavalli A, Fusco C, Iascone M, Van Maldergem L, Venkateswaran S, Zuffardi O, Vergano S, Garavelli L, Bayat A. Deep phenotyping of the neuroimaging and skeletal features in KBG syndrome: a study of 53 patients and review of the literature. J Med Genet 2023; 60:1224-1234. [PMID: 37586838 DOI: 10.1136/jmg-2023-109141] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/30/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND KBG syndrome is caused by haploinsufficiency of ANKRD11 and is characterised by macrodontia of upper central incisors, distinctive facial features, short stature, skeletal anomalies, developmental delay, brain malformations and seizures. The central nervous system (CNS) and skeletal features remain poorly defined. METHODS CNS and/or skeletal imaging were collected from molecularly confirmed individuals with KBG syndrome through an international network. We evaluated the original imaging and compared our results with data in the literature. RESULTS We identified 53 individuals, 44 with CNS and 40 with skeletal imaging. Common CNS findings included incomplete hippocampal inversion and posterior fossa malformations; these were significantly more common than previously reported (63.4% and 65.9% vs 1.1% and 24.7%, respectively). Additional features included patulous internal auditory canal, never described before in KBG syndrome, and the recurrence of ventriculomegaly, encephalic cysts, empty sella and low-lying conus medullaris. We found no correlation between these structural anomalies and epilepsy or intellectual disability. Prevalent skeletal findings comprised abnormalities of the spine including scoliosis, coccygeal anomalies and cervical ribs. Hand X-rays revealed frequent abnormalities of carpal bone morphology and maturation, including a greater delay in ossification compared with metacarpal/phalanx bones. CONCLUSION This cohort enabled us to describe the prevalence of very heterogeneous neuroradiological and skeletal anomalies in KBG syndrome. Knowledge of the spectrum of such anomalies will aid diagnostic accuracy, improve patient care and provide a reference for future research on the effects of ANKRD11 variants in skeletal and brain development.
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Affiliation(s)
- Francesca Peluso
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Stefano G Caraffi
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Gianluca Contrò
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Lara Valeri
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
- Department of Pediatrics, University of Modena and Reggio Emilia Faculty of Medicine and Surgery, Modena, Emilia-Romagna, Italy
| | - Manuela Napoli
- Neuroradiology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Giorgia Carboni
- Radiology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Alka Seth
- Radiology, Rigshospitalet, Kobenhavn, Denmark
| | - Roberta Zuntini
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Emanuele Coccia
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Guja Astrea
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, Toscana, Italy
| | - Anne-Marie Bisgaard
- Center for Rare Diseases, Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital, Kobenhavn, Denmark
| | - Ivan Ivanovski
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
| | - Silvia Maitz
- Service of Medical Genetics, IOSI, EOC, Lugano, Switzerland
| | | | - Melissa T Carter
- The University of Newcastle, Callaghan, New South Wales, Australia
| | - Maria Lisa Dentici
- Department of Clinical Genetics, Copenhagen University Hospital, Kobenhavn, Denmark
| | - Koenraad Devriendt
- Department for Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Melissa Bellini
- Department of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy
| | - Maria Cristina Digilio
- Department of Medical and Surgical Sciences of the Mother, Children and Adults, University of Modena and Reggio Emilia, Modena, Italy
| | - Asif Doja
- The University of Newcastle, Callaghan, New South Wales, Australia
| | - David A Dyment
- The University of Newcastle, Callaghan, New South Wales, Australia
| | - Stense Farholt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands
| | - Carlos R Ferreira
- Medical Genetics Unit, Centro Hospitalar e Universitário de Coimbra EPE, Coimbra, Coimbra, Portugal
| | - Lynne A Wolfe
- Medical Genetics Unit, Centro Hospitalar e Universitário de Coimbra EPE, Coimbra, Coimbra, Portugal
| | - William A Gahl
- National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Maria Gnazzo
- Translational Cytogenomics Research Unit, Laboratory of Medical Genetics, Bambino Gesu Pediatric Hospital, Roma, Lazio, Italy
| | - Himanshu Goel
- Hunter Genetics, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
- The University of Newcastle, Callaghan, New South Wales, Australia
| | - Sabine Weller Grønborg
- Center for Rare Diseases, Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital, Kobenhavn, Denmark
- Department of Clinical Genetics, Copenhagen University Hospital, Kobenhavn, Denmark
| | - Trine Hammer
- Department of Clinical Genetics, Copenhagen University Hospital, Kobenhavn, Denmark
- Department for Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Lorenzo Iughetti
- Department of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy
- Department of Medical and Surgical Sciences of the Mother, Children and Adults, University of Modena and Reggio Emilia, Modena, Italy
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands
| | - David A Koolen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands
| | - Francesca Romana Lepri
- Translational Cytogenomics Research Unit, Laboratory of Medical Genetics, Bambino Gesu Pediatric Hospital, Roma, Lazio, Italy
| | - Gabrielle Lemire
- Department of Genetics, Children's Hospital of Eastern Ontario (CHEO), Ottawa, Ontario, Canada
| | - Pedro Louro
- Medical Genetics Unit, Centro Hospitalar e Universitário de Coimbra EPE, Coimbra, Coimbra, Portugal
| | - Gary McCullagh
- Royal Manchester Children's Hospital and University of Manchester, Royal Manchester Children's Hospital, Manchester, Manchester, UK
| | - Simona F Madeo
- Department of Medical and Surgical Sciences of the Mother, Children and Adults, University of Modena and Reggio Emilia, Modena, Italy
| | - Annarita Milone
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, Toscana, Italy
| | - Roberta Milone
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, Toscana, Italy
| | - Jens Erik Klint Nielsen
- Department of Pediatrics, Zealand University Hospital Roskilde, Roskilde, Sjaelland, Denmark
| | - Antonio Novelli
- Translational Cytogenomics Research Unit, Laboratory of Medical Genetics, Bambino Gesu Pediatric Hospital, Roma, Lazio, Italy
| | - Charlotte W Ockeloen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands
| | - Rosario Pascarella
- Neuroradiology Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Tommaso Pippucci
- U.O. Genetica Medica, IRCCS Azienda Ospedaliero-Universitaria di Bologna Policlinico S Orsola, Bologna, Emilia-Romagna, Italy
| | - Ivana Ricca
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, Toscana, Italy
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Sarah Sawyer
- Department of Genetics, Children's Hospital of Eastern Ontario (CHEO), Ottawa, Ontario, Canada
| | | | - Sander Stegmann
- Department of Clinical Genetics and School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Maastricht, Limburg, Netherlands
| | - Constanze T Stumpel
- Department of Clinical Genetics and School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Maastricht, Limburg, Netherlands
| | - Amy Goel
- University of Newcastle, Callaghan, The University of Newcastle, Callaghan, New South Wales, Australia
| | - Juliet M Taylor
- Genetic Health Service - Northern Hub, Genetic Health Service - Northern Hub, Aukland, New Zealand
| | - Domenico Barbuti
- Radiology and Bioimaging Unit, Bambino Gesu Pediatric Hospital, Roma, Lazio, Italy
| | - Annarosa Soresina
- Paediatrics Clinic and Institute for Molecular Medicine A. Nocivelli, Department of Clinical and Ex-perimental Sciences, ASST Spedali Civili di Brescia, Brescia, Lombardia, Italy
| | | | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Calambrone, Toscana, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Toscana, Italy
| | - Anna Cavalli
- Child Neurology and Psychiatry Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Carlo Fusco
- Child Neurology and Psychiatry Unit, Azienda USL - IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Maria Iascone
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, Bergamo, Lombardia, Italy
| | - Lionel Van Maldergem
- Centre de génétique humaine, Université de Franche-Comté, Centre Hospitalier Universitaire de Besancon, Besancon, France
| | | | - Orsetta Zuffardi
- Department of Molecular Medicine, University of Pavia, Pavia, Lombardia, Italy
| | - Samantha Vergano
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, Virginia, USA
| | - Livia Garavelli
- Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Emilia-Romagna, Italy
| | - Allan Bayat
- Department for Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services Research, University of Southern Denmark, Odense, Syddanmark, Denmark
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Franceschi R, Rivieri F, Novelli A, Ferretti D, Anesi A, Soffiati M, Porretti G, Maines E, Mucciolo M, Radetti G. Mosaicism of a novel variant in the ANKRD11 gene in a child with a mild KBG phenotype: A case report. World J Med Genet 2023; 11:21-27. [DOI: 10.5496/wjmg.v11.i2.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/03/2023] [Accepted: 05/19/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND KBG syndrome is likely underdiagnosed because of mild and non-specific features in some affected patients especially before the upper permanent central incisors eruption at about the age of 7-8 years. Somatic mosaicisms are usually recognized in the parents only after a typically affected son is diagnosed with KBG syndrome. We describe for the first time the mosaicism of a novel variant in a child with a mild KBG phenotype.
CASE SUMMARY Our patient presented at 24 mo of age with short stature, hand abnormalities, facial dysmorphism and mild developmental delay. Pituitary hypoplasia and central hypothyroidism were also detected. By next generation sequencing (NGS) analysis we found a novel deletion in the ANKRD11 gene (c.4880_4893del.), that can be classified as likely pathogenic for the syndrome, with the percentage of mutated allele of 36%. We considered this finding as causative of the mild and non-specific phenotype for KBG syndrome in our patient, as previously reported in adults. A heterozygous variant in HESX1 gene, classified as variant of uncertain significance, but suspected of causing pituitary hypoplasia and hormonal deficiency, was also found. The patient started levothyroxine and growth hormone treatment.
CONCLUSION The increased use of NGS analysis may expand the phenotypic spectrum of KBG syndrome because it allows genetic diagnosis of somatic mosaicisms also in children.
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Affiliation(s)
- Roberto Franceschi
- Department of Pediatrics, S. Chiara Hospital of Trento, APSS, Trento 38122, Italy
| | - Francesca Rivieri
- Genetic Unit, Laboratory of Clinical Pathology, Department of Laboratories, APSS, Trento 38122, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Ospedale Pediatrico Bambino Gesù, Rome 00165, Italy
| | - Daniele Ferretti
- Human Genetics Laboratory, Ospedale Pediatrico Bambino Gesù, Rome 00165, Italy
| | - Adriano Anesi
- Genetic Unit, Laboratory of Clinical Pathology, Department of Laboratories, APSS, Trento 38122, Italy
| | - Massimo Soffiati
- Department of Pediatrics, S. Chiara General Hospital, APSS, Trento 38122, Italy
| | - Giulia Porretti
- Department of Radiology, S. Chiara General Hospital, APSS, Trento 38122, Italy
| | - Evelina Maines
- Department of Pediatrics, S. Chiara General Hospital, APSS, Trento 38122, Italy
| | - Mafalda Mucciolo
- Human Genetics Laboratory, Ospedale Pediatrico Bambino Gesù, Rome 00165, Italy
| | - Giorgio Radetti
- Department of Pediatrics, General Hospital Bolzano, Marienklinik, Bolzano 39100, Italy
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Choi Y, Choi J, Do H, Hwang S, Seo GH, Choi IH, Keum C, Choi JH, Kang M, Kim GH, Yoo HW, Lee BH. KBG syndrome: Clinical features and molecular findings in seven unrelated Korean families with a review of the literature. Mol Genet Genomic Med 2022; 11:e2127. [PMID: 36564961 PMCID: PMC10094073 DOI: 10.1002/mgg3.2127] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/27/2022] [Accepted: 12/15/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND KBG syndrome is a rare genetic disorder involving macrodontia of the upper central incisors, craniofacial, skeletal, and neurologic symptoms, caused either by a heterozygous variant in ANKRD11 or deletion of 16q24.3, including ANKRD11. Diagnostic criteria were proposed in 2007 based on 50 cases, but KBG syndrome remains underdiagnosed. METHODS Whole exome sequencing (WES) and array comparative genomic hybridization (array CGH) were conducted for genetic analysis and patient phenotypes were characterized based on medical records. RESULTS Eight patients from seven unrelated families were confirmed with KBG syndrome. All patients (8/8, 100%) had some degree of craniofacial dysmorphism and developmental delay or intellectual disabilities. Triangular face, synophrys, anteverted nostril, prominent ears, long philtrum, and tented upper lip, which are typical facial dysmorphism findings in patients with KBG syndrome, were uniformly identified in the eight patients participating in this study, with co-occurrence rates of 4/8 (50%), 4/8 (50%), 4/8 (50%), 4/8 (50%), 5/8 (62.5%), and 5/8 (62.5%), respectively. Various clinical manifestations not included in the diagnostic criteria were observed. Six patients had point mutations in ANKRD11, one had an exonic deletion of ANKRD11, and one had a 16q24.3 microdeletion. According to the ACMG guidelines, all mutations were classified as pathogenic. The c.2454dup (p.Asn819fs*1) mutation in Pt 4 was reported previously. The remaining variants (c.397 + 1G>A, c.226 + 1G>A, c.2647del (p.Glu883Argfs*94), and c.4093C>T (p.Arg1365Ter)) were novel. CONCLUSION The clinical and molecular features of eight patients from seven unrelated Korean families with KBG syndrome described here will assist physicians in understanding this rare genetic condition.
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Affiliation(s)
- Yunha Choi
- Department of Pediatrics, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Jungmin Choi
- Medical Genetics Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Hyosang Do
- Medical Genetics Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Soojin Hwang
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | | | - In Hee Choi
- Department of Genetic Counseling, University of Ulsan College of Medicine, Seoul, South Korea
| | | | - Jin-Ho Choi
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Minji Kang
- Medical Genetics Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Gu-Hwan Kim
- Medical Genetics Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Han-Wook Yoo
- Department of Pediatrics, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Beom Hee Lee
- Medical Genetics Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.,Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
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