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Kennedy J, Goudie D, Blair E, Chandler K, Joss S, McKay V, Green A, Armstrong R, Lees M, Kamien B, Hopper B, Tan TY, Yap P, Stark Z, Okamoto N, Miyake N, Matsumoto N, Macnamara E, Murphy JL, McCormick E, Hakonarson H, Falk MJ, Li D, Blackburn P, Klee E, Babovic-Vuksanovic D, Schelley S, Hudgins L, Kant S, Isidor B, Cogne B, Bradbury K, Williams M, Patel C, Heussler H, Duff-Farrier C, Lakeman P, Scurr I, Kini U, Elting M, Reijnders M, Schuurs-Hoeijmakers J, Wafik M, Blomhoff A, Ruivenkamp CAL, Nibbeling E, Dingemans AJM, Douine ED, Nelson SF, Hempel M, Bierhals T, Lessel D, Johannsen J, Arboleda VA, Newbury-Ecob R. KAT6A Syndrome: genotype-phenotype correlation in 76 patients with pathogenic KAT6A variants. Genet Med 2019; 21:850-860. [PMID: 30245513 PMCID: PMC6634310 DOI: 10.1038/s41436-018-0259-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/26/2018] [Indexed: 01/27/2023] Open
Abstract
PURPOSE Pathogenic variants in KAT6A have recently been identified as a cause of syndromic developmental delay. Within 2 years, the number of patients identified with pathogenic KAT6A variants has rapidly expanded and the full extent and variability of the clinical phenotype has not been reported. METHODS We obtained data for patients with KAT6A pathogenic variants through three sources: treating clinicians, an online family survey distributed through social media, and a literature review. RESULTS We identified 52 unreported cases, bringing the total number of published cases to 76. Our results expand the genotypic spectrum of pathogenic variants to include missense and splicing mutations. We functionally validated a pathogenic splice-site variant and identified a likely hotspot location for de novo missense variants. The majority of clinical features in KAT6A syndrome have highly variable penetrance. For core features such as intellectual disability, speech delay, microcephaly, cardiac anomalies, and gastrointestinal complications, genotype- phenotype correlations show that late-truncating pathogenic variants (exons 16-17) are significantly more prevalent. We highlight novel associations, including an increased risk of gastrointestinal obstruction. CONCLUSION Our data expand the genotypic and phenotypic spectrum for individuals with genetic pathogenic variants in KAT6A and we outline appropriate clinical management.
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Affiliation(s)
- Joanna Kennedy
- Clinical Genetics, University Hospitals Bristol, Southwell St, Bristol, UK
- University of Bristol, Bristol, UK
| | - David Goudie
- Clinical Genetics, Ninewells Hospital & Medical School, Dundee, UK
| | - Edward Blair
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Department of Clinical Genetics, Churchill Hospital, Headington, Oxford, UK
| | - Kate Chandler
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Central Manchester Foundation NHS Trust, Manchester Academic Health Science Centre (MAHSC), Manchester, UK
| | - Shelagh Joss
- West of Scotland Genetics Service, Queen Elizabeth University Hospital, Glasgow, UK
| | - Victoria McKay
- Cheshire & Merseyside Regional Genetics Service, Liverpool Women's NHS Foundation Trust, Crown Street, Liverpool, UK
| | - Andrew Green
- Department of Clinical Genetics, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Ruth Armstrong
- East Anglian Medical Genetics Service, Addenbrooke's Hospital, Cambridge, UK
| | - Melissa Lees
- Clinical Genetics, Great Ormond Street Hospital NHS Trust, London, UK
| | | | | | - Tiong Yang Tan
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Patrick Yap
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
- Genetic Health Service New Zealand, Auckland, New Zealand
| | - Zornitza Stark
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center, Osaka, Japan
- Research Institute for Maternal and Child Health, Osaka Medical Center, Osaka, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ellen Macnamara
- National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | | | - Elizabeth McCormick
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Marni J Falk
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Dong Li
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Eric Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Dusica Babovic-Vuksanovic
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Susan Schelley
- Division of Medical Genetics, Department of Pediatrics, Stanford University, Stanford, CA, USA
| | - Louanne Hudgins
- Division of Medical Genetics, Department of Pediatrics, Stanford University, Stanford, CA, USA
| | - Sarina Kant
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Benjamin Cogne
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - Kimberley Bradbury
- Clinical Genetics Guys and St Thomas' NHS Foundation Trust, Guys Hospital, London, UK
| | - Mark Williams
- Molecular Diagnostics, Mater Group, South Brisbane, Queensland, Australia
| | - Chirag Patel
- Genetic Health Queensland, Herston, Brisbane, Queensland, Australia
| | - Helen Heussler
- Child Development Service, Lady Cilento Children's Hospital, Brisbane, Queensland, Australia
| | | | - Phillis Lakeman
- Academic Medical Center, Department of Clinical Genetics, Amsterdam, The Netherlands
| | - Ingrid Scurr
- Clinical Genetics, University Hospitals Bristol, Southwell St, Bristol, UK
| | - Usha Kini
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Department of Clinical Genetics, Churchill Hospital, Headington, Oxford, UK
| | - Mariet Elting
- Klinisch Geneticus, VU Medisch centrum, Amsterdam, The Netherlands
| | - Margot Reijnders
- Radboud University Medical Center, Department of Human Genetics, Nijmegen, The Netherlands
| | | | - Mohamed Wafik
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Department of Clinical Genetics, Churchill Hospital, Headington, Oxford, UK
| | - Anne Blomhoff
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | | | - Esther Nibbeling
- Department of Genetics, University of Groningen, Groningen, The Netherlands
| | | | - Emilie D Douine
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Stanley F Nelson
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Davor Lessel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Jessika Johannsen
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Valerie A Arboleda
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
| | - Ruth Newbury-Ecob
- Clinical Genetics, University Hospitals Bristol, Southwell St, Bristol, UK.
- University of Bristol, Bristol, UK.
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Mero IL, Mørk HH, Sheng Y, Blomhoff A, Opheim GL, Erichsen A, Vigeland MD, Selmer KK. Homozygous KIDINS220 loss-of-function variants in fetuses with cerebral ventriculomegaly and limb contractures. Hum Mol Genet 2018; 26:3792-3796. [PMID: 28934391 DOI: 10.1093/hmg/ddx263] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/03/2017] [Indexed: 12/30/2022] Open
Abstract
Heterozygous mutations in KIDINS220 were recently suggested a cause of spastic paraplegia, intellectual disability, nystagmus and obesity. All patients carried terminal nonsense de novo mutations that seemed to escape nonsense-mediated mRNA decay. The mechanism for pathogenicity is yet unexplained, as it seems that heterozygous loss-of-function variants of KIDINS220 are generally well tolerated. We present a consanguineous couple who experienced four pregnancy terminations due to repeated findings in the fetuses comprising enlarged cerebral ventricles and limb contractures. Exome sequencing in two of the aborted fetuses revealed a shared homozygous frameshift variant in exon 24 in KIDINS220. Sanger sequencing of the variant in available family members showed complete segregation with the affection status, resulting in a LOD score of 2.5 under an autozygous inheritance model. mRNA studies revealed destruction of the original splice site, resulting in an out-of-frame transcript and introduction of a premature termination codon in exon 25. Premature termination codons in this position are likely to cause activation of nonsense-mediated mRNA decay and result in complete absence of KIDINS220 protein in individuals homozygous for the variant. The phenotype of the presented fetuses overlaps with findings in functional studies of knockout Kidins220 mice embryos that are non-viable with enlarged cerebral ventricles. The human fetuses also exhibit several similarities to the milder phenotype described in patients with heterozygous KIDINS220 mutations. We hence propose that the identified homozygous loss-of-function variant in KIDINS220 causes the phenotype in the presented fetuses, and that this represents a hitherto undescribed severe autosomal recessive neurodevelopmental disorder.
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Affiliation(s)
- I-L Mero
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - H H Mørk
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Y Sheng
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway.,Department of Medical Genetics, University of Oslo, Oslo, Norway
| | - A Blomhoff
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | | | - Aa Erichsen
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - M D Vigeland
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway.,Department of Medical Genetics, University of Oslo, Oslo, Norway
| | - K K Selmer
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway.,Department of Medical Genetics, University of Oslo, Oslo, Norway
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Pedurupillay CRJ, Amundsen SS, Barøy T, Rasmussen M, Blomhoff A, Stadheim BF, Ørstavik K, Holmgren A, Iqbal T, Frengen E, Misceo D, Strømme P. Clinical and molecular characteristics in three families with biallelic mutations in IGHMBP2. Neuromuscul Disord 2016; 26:570-5. [PMID: 27450922 DOI: 10.1016/j.nmd.2016.06.457] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 06/09/2016] [Accepted: 06/20/2016] [Indexed: 11/28/2022]
Abstract
Biallelic mutations in IGHMBP2 cause spinal muscular atrophy with respiratory distress type 1 (SMARD1) or Charcot-Marie-Tooth type 2S (CMT2S). We report three families variably affected by IGHMBP2 mutations. Patient 1, an 8-year-old boy with two homozygous variants: c.2T>C and c.861C>G, was wheelchair bound due to sensorimotor axonal neuropathy and chronic respiratory failure. Patient 2 and his younger sister, Patient 3, had compound heterozygous variants: c.983_987delAAGAA and c.1478C>T. However, clinical phenotypes differed markedly as the elder with sensorimotor axonal neuropathy had still unaffected respiratory function at 4.5 years, whereas the younger presented as infantile spinal muscular atrophy and died from relentless respiratory failure at 11 months. Patient 4, a 6-year-old girl homozygous for IGHMBP2 c.449+1G>T documented to result in two aberrant transcripts, was wheelchair dependent due to axonal polyneuropathy. The clinical presentation in Patients 1 and 3 were consistent with SMARD1, whereas Patients 2 and 4 were in agreement with CMT2S.
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Affiliation(s)
- Christeen Ramane J Pedurupillay
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Silja S Amundsen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Tuva Barøy
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Magnhild Rasmussen
- Women and Children's Division, Department of Clinical Neurosciences for Children, Oslo University Hospital, Oslo, Norway; Unit for Congenital and Hereditary Neuromuscular Disorders, Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Anne Blomhoff
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Barbro Fossøy Stadheim
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | | | - Asbjørn Holmgren
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Tahir Iqbal
- Molecular Biology laboratory, Department of Zoology, University of Gujrat, Gujrat, Pakistan
| | - Eirik Frengen
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Doriana Misceo
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Petter Strømme
- Faculty of Medicine, University of Oslo, Oslo, Norway; Women and Children's Division, Department of Clinical Neurosciences for Children, Oslo University Hospital, Oslo, Norway.
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Barøy T, Misceo D, Strømme P, Stray-Pedersen A, Holmgren A, Rødningen OK, Blomhoff A, Helle JR, Stormyr A, Tvedt B, Fannemel M, Frengen E. Haploinsufficiency of two histone modifier genes on 6p22.3, ATXN1 and JARID2, is associated with intellectual disability. Orphanet J Rare Dis 2013; 8:3. [PMID: 23294540 PMCID: PMC3675438 DOI: 10.1186/1750-1172-8-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 01/03/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nineteen patients with deletions in chromosome 6p22-p24 have been published so far. The syndromic phenotype is varied, and includes intellectual disability, behavioural abnormalities, dysmorphic features and structural organ defects. Heterogeneous deletion breakpoints and sizes (1-17 Mb) and overlapping phenotypes have made the identification of the disease causing genes challenging. We suggest JARID2 and ATXN1, both harbored in 6p22.3, as disease causing genes. METHODS AND RESULTS We describe five unrelated patients with de novo deletions (0.1-4.8 Mb in size) in chromosome 6p22.3-p24.1 detected by aCGH in a cohort of approximately 3600 patients ascertained for neurodevelopmental disorders. Two patients (Patients 4 and 5) carried non-overlapping deletions that were encompassed by the deletions of the remaining three patients (Patients 1-3), indicating the existence of two distinct dosage sensitive genes responsible for impaired cognitive function in 6p22.3 deletion-patients. The smallest region of overlap (SRO I) in Patients 1-4 (189 kb) included the genes JARID2 and DTNBP1, while SRO II in Patients 1-3 and 5 (116 kb) contained GMPR and ATXN1. Patients with deletion of SRO I manifested variable degrees of cognitive impairment, gait disturbance and distinct, similar facial dysmorphic features (prominent supraorbital ridges, deep set eyes, dark infraorbital circles and midface hypoplasia) that might be ascribed to the haploinsufficiency of JARID2. Patients with deletion of SRO II showed intellectual disability and behavioural abnormalities, likely to be caused by the deletion of ATXN1. Patients 1-3 presented with lower cognitive function than Patients 4 and 5, possibly due to the concomitant haploinsufficiency of both ATXN1 and JARID2. The chromatin modifier genes ATXN1 and JARID2 are likely candidates contributing to the clinical phenotype in 6p22-p24 deletion-patients. Both genes exert their effect on the Notch signalling pathway, which plays an important role in several developmental processes. CONCLUSIONS Patients carrying JARID2 deletion manifested with cognitive impairment, gait disturbance and a characteristic facial appearance, whereas patients with deletion of ATXN1 seemed to be characterized by intellectual disability and behavioural abnormalities. Due to the characteristic facial appearance, JARID2 haploinsufficiency might represent a clinically recognizable neurodevelopmental syndrome.
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Affiliation(s)
- Tuva Barøy
- Department of Medical Genetics, University of Oslo, P,O, Box 1036, Blindern, Oslo N-0315, Norway
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