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Silveira KC, Fonseca IC, Oborn C, Wengryn P, Ghafoor S, Beke A, Dreseris ES, Wong C, Iacovone A, Soltys CL, Babul-Hirji R, Artigalas O, Antolini-Tavares A, Gingras AC, Campos E, Cavalcanti DP, Kannu P. CYP26B1-related disorder: expanding the ends of the spectrum through clinical and molecular evidence. Hum Genet 2023; 142:1571-1586. [PMID: 37755482 PMCID: PMC10602971 DOI: 10.1007/s00439-023-02598-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/03/2023] [Indexed: 09/28/2023]
Abstract
CYP26B1 metabolizes retinoic acid in the developing embryo to regulate its levels. A limited number of individuals with pathogenic variants in CYP26B1 have been documented with a varied phenotypic spectrum, spanning from a severe manifestation involving skull anomalies, craniosynostosis, encephalocele, radio-humeral fusion, oligodactyly, and a narrow thorax, to a milder presentation characterized by craniosynostosis, restricted radio-humeral joint mobility, hearing loss, and intellectual disability. Here, we report two families with CYP26B1-related phenotypes and describe the data obtained from functional studies of the variants. Exome and Sanger sequencing were used for variant identification in family 1 and family 2, respectively. Family 1 reflects a mild phenotype, which includes craniofacial dysmorphism with brachycephaly (without craniosynostosis), arachnodactyly, reduced radioulnar joint movement, conductive hearing loss, learning disability-and compound heterozygous CYP26B1 variants: (p.[(Pro118Leu)];[(Arg234Gln)]) were found. In family 2, a stillborn fetus presented a lethal phenotype with spina bifida occulta, hydrocephalus, poor skeletal mineralization, synostosis, limb defects, and a synonymous homozygous variant in CYP26B1: c.1083C > A. A minigene assay revealed that the synonymous variant created a new splice site, removing part of exon 5 (p.Val361_Asp382del). Enzymatic activity was assessed using a luciferase assay, demonstrating a notable reduction in exogenous retinoic acid metabolism for the variant p.Val361_Asp382del. (~ 3.5 × decrease compared to wild-type); comparatively, the variants p.(Pro118Leu) and p.(Arg234Gln) demonstrated a partial loss of metabolism (1.7× and 2.3× reduction, respectively). A proximity-dependent biotin identification assay reaffirmed previously reported ER-resident protein interactions. Additional work into these interactions is critical to determine if CYP26B1 is involved with other biological events on the ER. Immunofluorescence assay suggests that mutant CYP26B1 is still localized in the endoplasmic reticulum. These results indicate that novel pathogenic variants in CYP26B1 result in varying levels of enzymatic activity that impact retinoic acid metabolism and relate to the distinct phenotypes observed.
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Affiliation(s)
- Karina C Silveira
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Inara Chacon Fonseca
- Clinical Genetics, Durham Region Cancer Centre, Lakeridge Health Oshawa, Oshawa, ON, L1G 2B9, Canada
| | - Connor Oborn
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Parker Wengryn
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Saima Ghafoor
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Alexander Beke
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Ema S Dreseris
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Cassandra Wong
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
| | - Aline Iacovone
- Skeletal Dysplasia Group, Medical Genetics Area, Translational Medicine Department, FCM, University of Campinas (UNICAMP), R. Tessália V de Camargo, 126, Campinas, SP, 13083-887, Brazil
| | - Carrie-Lynn Soltys
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Riyana Babul-Hirji
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Osvaldo Artigalas
- Clinical Genetics Unit, Children's Hospital, Grupo Hospitalar Conceicao, Porto Alegre, Brazil
| | | | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Eric Campos
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Denise P Cavalcanti
- Skeletal Dysplasia Group, Medical Genetics Area, Translational Medicine Department, FCM, University of Campinas (UNICAMP), R. Tessália V de Camargo, 126, Campinas, SP, 13083-887, Brazil.
| | - Peter Kannu
- Department of Medical Genetics, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
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Silveira KC, Kanazawa TY, Silveira C, Lacarrubba-Flores MDJ, Carvalho BS, Cavalcanti DP. Molecular diagnosis in a cohort of 114 patients with rare skeletal dysplasias. Am J Med Genet C Semin Med Genet 2021; 187:396-408. [PMID: 34529350 DOI: 10.1002/ajmg.c.31937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/31/2021] [Accepted: 09/07/2021] [Indexed: 12/14/2022]
Abstract
Molecular diagnosis is important to provide accurate genetic counseling of skeletal dysplasias (SD). Although next-generation sequencing (NGS) techniques are currently the preferred methods for analyzing these conditions, some of the published results have not shown a detection rate as high as it would be expected. The present study aimed to assess the diagnostic yield of targeted NGS combined with Sanger sequencing (SS) for low-coverage exons of genes of interest and exome sequencing (ES) in a series of patients with rare SD and use two patients as an example of our strategy. This study used two different in-house panels. Of 93 variants found in 88/114 (77%) patients, 57 are novel. The pathogenic variants found in the following genes: B3GALT6, PCYT1A, INPPL1, LIFR, of four patients were only detected by SS. In conclusion, the high diagnostic yield reached in the present study can be attributed to both a good selection of patients and the utilization of the SS for the insufficiently covered regions. Additionally, the two case reports-a patient with acrodysostosis related to PRKAR1A and another with ciliopathy associated with KIAA0753, add new and relevant clinical information to the current knowledge.
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Affiliation(s)
- Karina C Silveira
- Skeletal Dysplasias Group, Department of Translational Medicine, Medical Genetics, University of Campinas (UNICAMP), Campinas, Brazil
| | - Thatiane Y Kanazawa
- Skeletal Dysplasias Group, Department of Translational Medicine, Medical Genetics, University of Campinas (UNICAMP), Campinas, Brazil
| | - Cynthia Silveira
- Skeletal Dysplasias Group, Department of Translational Medicine, Medical Genetics, University of Campinas (UNICAMP), Campinas, Brazil
| | - Maria D J Lacarrubba-Flores
- Skeletal Dysplasias Group, Department of Translational Medicine, Medical Genetics, University of Campinas (UNICAMP), Campinas, Brazil
| | - Benilton S Carvalho
- Department of Statistics, Institute of Mathematics, Statistics and Scientific Computing, University of Campinas (UNICAMP), Campinas, Brazil
| | - Denise P Cavalcanti
- Skeletal Dysplasias Group, Department of Translational Medicine, Medical Genetics, University of Campinas (UNICAMP), Campinas, Brazil
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Cavalcanti DP, Fano V, Mellado C, Lacarrubba-Flores MDJ, Silveira C, Silveira KC, del Pino M, Moresco A, Caino S, Mejía RR, García CJ, Lay-Son G, Ferreira CR. Skeletal dysplasias in Latin America. Am J Med Genet C Semin Med Genet 2020; 184:986-995. [PMID: 33219737 PMCID: PMC9827228 DOI: 10.1002/ajmg.c.31861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 11/05/2020] [Accepted: 11/10/2020] [Indexed: 01/11/2023]
Abstract
Skeletal dysplasias (SD) are disturbances in growth due to defects intrinsic to the bone and/or cartilage, usually affecting multiple bones and having a progressive character. In this article, we review the state of clinical and research SD resources available in Latin America, including three specific countries (Brazil, Argentina, and Chile), that have established multidisciplinary clinics for the care of these patients. From the epidemiological point of view, the SD prevalence of 3.2 per 10,000 births from nine South American countries included in the ECLAMC network represents the most accurate estimate not just in Latin America, but worldwide. In Brazil, there are currently five groups focused on SD. The data from one of these groups including the website www.ocd.med.br, created to assist in the diagnosis of SD, are highlighted showing that telemedicine for this purpose represents a good strategy for the region. The experience of more than 30 years of the SD multidisciplinary clinic in an Argentinian Hospital is presented, evidencing a solid experience mainly in the follow-up of the most frequent SD, especially those belonging the FGFR3 group and OI. In Chile, a group with 20 years of experience presents its work with geneticists and pediatricians, focusing on diagnostic purposes and clinical management. Altogether, although SD health-care and research activities in Latin America are in their early stages, the experience in these three countries seems promising and stimulating for the region as a whole.
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Affiliation(s)
- Denise P. Cavalcanti
- Skeletal Dysplasia Group, Medical Genetics Department, Medical Sciences Faculty, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Virginia Fano
- Growth and Development Department, Garrahan Hospital, Buenos Aires, Argentina
| | - Cecilia Mellado
- Study Group of Genetic Skeletal Abnormalities, Genetic Unit, Pediatrics Division, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maria Dora J. Lacarrubba-Flores
- Skeletal Dysplasia Group, Medical Genetics Department, Medical Sciences Faculty, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cynthia Silveira
- Skeletal Dysplasia Group, Medical Genetics Department, Medical Sciences Faculty, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Karina C. Silveira
- Skeletal Dysplasia Group, Medical Genetics Department, Medical Sciences Faculty, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Mariana del Pino
- Growth and Development Department, Garrahan Hospital, Buenos Aires, Argentina
| | | | - Silvia Caino
- Growth and Development Department, Garrahan Hospital, Buenos Aires, Argentina
| | - Rosario Ramos Mejía
- Growth and Development Department, Garrahan Hospital, Buenos Aires, Argentina
| | - Cristián J. García
- Study Group of Genetic Skeletal Abnormalities, Department of Radiology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Guillermo Lay-Son
- Study Group of Genetic Skeletal Abnormalities, Genetic Unit, Pediatrics Division, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carlos R. Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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Silveira KC, Moreno CA, Cavalcanti DP. Beemer-Langer syndrome is a ciliopathy due to biallelic mutations in IFT122. Am J Med Genet A 2017; 173:1186-1189. [PMID: 28370949 DOI: 10.1002/ajmg.a.38157] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 09/29/2016] [Revised: 11/10/2016] [Accepted: 01/08/2017] [Indexed: 11/09/2022]
Abstract
Since most short-rib polydactyly phenotypes are due to genes involved with biogenesis and maintenance of the primary cilium, this group of skeletal dysplasias was recently designated as ciliopathies with major skeletal involvement. Beemer-Langer syndrome or short-rib polydactyly type IV, was first described in 1983, and has, thus far, remained without a defined molecular basis. The most recent classification of the skeletal dysplasias referred to this phenotype as an as-yet unproven ciliopathy. IFT122 is a gene that encodes a protein responsible for the retrograde transport along the cilium; it has been associated with this group of skeletal dysplasias. To date, mutations in this gene were only found in Sensenbrenner syndrome. Using a panel of skeletal dysplasias genes, including 11 related to SRP, we identified biallelic mutations in IFT122 ([c.3184G>C];[c.3228dupG;c.3231_3233delCAT]) in a fetus with a typical phenotype of SRP-IV, finally confirmed that this phenotype is a ciliopathy and adding to the list of ciliopathies with major skeletal involvement.
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Affiliation(s)
- Karina C Silveira
- Department of Medical Genetics, Skeletal Dysplasia Group, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Carolina A Moreno
- Department of Medical Genetics, Skeletal Dysplasia Group, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Department of Medical Genetics, Perinatal Genetic Program, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Denise P Cavalcanti
- Department of Medical Genetics, Skeletal Dysplasia Group, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Department of Medical Genetics, Perinatal Genetic Program, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
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