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Sinajon P, Chitayat D, Roifman M, Wasim S, Carmona S, Ryan G, Noor A, Kolomietz E, Chong K. Microarray and RASopathy-disorder testing in fetuses with increased nuchal translucency. Ultrasound Obstet Gynecol 2020; 55:383-390. [PMID: 31115076 DOI: 10.1002/uog.20352] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 05/03/2019] [Accepted: 05/10/2019] [Indexed: 06/09/2023]
Abstract
OBJECTIVES To determine the incidence of chromosomal abnormalities, submicroscopic chromosomal abnormalities and RASopathy-disorder (RD) pathogenic variants in a cohort of pregnancies with nuchal translucency thickness (NT) ≥ 3.5 mm, and to propose a clinical protocol for surveillance of this group of patients. METHODS This was a retrospective chart review of patients referred to The Prenatal Diagnosis and Medical Genetics Program at Mount Sinai Hospital between January 2013 and December 2015, due to NT ≥ 3.5 mm, who underwent chorionic villus sampling or amniocentesis. Patients underwent extensive genetic counseling prior to invasive procedures and testing. Quantitative fluorescence polymerase chain reaction (QF-PCR) was performed as the first-line test for aneuploidy. If the result was negative, patients underwent karyotyping and/or chromosomal microarray analysis (CMA), and if the findings were normal, they had testing for RD pathogenic variants, which included nine known genes. Patients also underwent detailed fetal ultrasound examinations and echocardiography, performed by expert operators. RESULTS A total of 226 eligible patients were identified. In 116/226 (51.3%) patients, QF-PCR identified a chromosomal aneuploidy. The remaining 110/226 (48.7%) patients had further genetic testing. Karyotyping/CMA detected an abnormal/pathogenic cytogenetic result in 9/110 (8.2%) patients, as well as five variants of unknown significance (VOUS). RD testing yielded three pathogenic variants (3/103), giving a detection rate of 2.9%, and one VOUS. The optimal NT cut-off for RD screening was 7.9 mm in this population. In 92/110 (83.6%) patients, the genetic investigations were normal. Of these pregnancies, an early (14-16 weeks' gestation) detailed fetal ultrasound examination identified a structural abnormality in 24 (26.1%), 15 (16.3%) had an abnormal detailed ultrasound examination at 18-22 weeks' gestation and fetal echocardiography showed a cardiac abnormality in nine (9.8%). The birth outcome in the 83 pregnancies that had normal genetic investigations and known outcome included seven (8.4%) cases of termination of pregnancy, seven (8.4%) cases of intrauterine fetal death and 69 (83.1%) cases of live birth. Nine (9.8%) patients were lost to follow-up. CONCLUSIONS Both CMA and molecular testing for RD are important investigations in pregnancies with NT ≥ 3.5 mm. The use of genetic testing combined with fetal ultrasound examination provides valuable information that can influence pregnancy outcome, and provide recurrence risks, in this patient population. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
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Affiliation(s)
- P Sinajon
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - D Chitayat
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - M Roifman
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - S Wasim
- University Health Network, Toronto, Ontario, Canada
| | - S Carmona
- Medical Informatics Information Services, Joseph and Wolf Lebovic Health Complex, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - G Ryan
- Fetal Medicine Unit, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - A Noor
- Division of Diagnostic Medical Genetics, Department of Pathology and Laboratory Medicine, Joseph and Wolf Lebovic Health Complex, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - E Kolomietz
- Division of Diagnostic Medical Genetics, Department of Pathology and Laboratory Medicine, Joseph and Wolf Lebovic Health Complex, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - K Chong
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Roifman M, Marcelis CLM, Paton T, Marshall C, Silver R, Lohr JL, Yntema HG, Venselaar H, Kayserili H, van Bon B, Seaward G, Brunner HG, Chitayat D. De novo WNT5A-associated autosomal dominant Robinow syndrome suggests specificity of genotype and phenotype. Clin Genet 2014; 87:34-41. [PMID: 24716670 DOI: 10.1111/cge.12401] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [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: 01/26/2014] [Revised: 03/30/2014] [Accepted: 04/07/2014] [Indexed: 11/27/2022]
Abstract
Robinow Syndrome (RS), a rare skeletal dysplasia syndrome, is characterized by dysmorphic features resembling a fetal face, mesomelic limb shortening, hypoplastic external genitalia in males, and renal and vertebral anomalies. Both autosomal dominant and autosomal recessive patterns of inheritance have been reported. Since the description of autosomal dominant Robinow Syndrome (ADRS; OMIM 180700) in 1969 by Meinhard Robinow and colleagues, the molecular etiology remained elusive until only recently. WNT5A was proposed to be the candidate gene for ADRS, as mutations were found in two affected families, one of those being the originally described index family. We report three families with RS caused by novel heterozygous WNT5A mutations, which were confirmed in the first family by whole exome sequencing, and in all by Sanger sequencing. To our knowledge, this is the largest number of published families with ADRS in whom a WNT5A mutation was identified. Families 1 and 2 are the first cases showing de novo inheritance in the affected family members and thus strengthen the evidence for WNT5A as the causative gene in ADRS. Finally, we propose WNT5A mutation specificity in ADRS, which may affect interactions with other proteins in the Wnt pathway.
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Affiliation(s)
- M Roifman
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, ON, Canada; Division of Clinical and Metabolic Genetics, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
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