1
|
Welch CL, Aldred MA, Balachandar S, Dooijes D, Eichstaedt CA, Gräf S, Houweling AC, Machado RD, Pandya D, Prapa M, Shaukat M, Southgate L, Tenorio-Castano J, Chung WK. Defining the clinical validity of genes reported to cause pulmonary arterial hypertension. Genet Med 2023; 25:100925. [PMID: 37422716 PMCID: PMC10766870 DOI: 10.1016/j.gim.2023.100925] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/26/2023] [Accepted: 06/29/2023] [Indexed: 07/10/2023] Open
Abstract
PURPOSE Pulmonary arterial hypertension (PAH) is a rare, progressive vasculopathy with significant cardiopulmonary morbidity and mortality. Genetic testing is currently recommended for adults diagnosed with heritable, idiopathic, anorexigen-, hereditary hemorrhagic telangiectasia-, and congenital heart disease-associated PAH, PAH with overt features of venous/capillary involvement, and all children diagnosed with PAH. Variants in at least 27 genes have putative evidence for PAH causality. Rigorous assessment of the evidence is needed to inform genetic testing. METHODS An international panel of experts in PAH applied a semi-quantitative scoring system developed by the NIH Clinical Genome Resource to classify the relative strength of evidence supporting PAH gene-disease relationships based on genetic and experimental evidence. RESULTS Twelve genes (BMPR2, ACVRL1, ATP13A3, CAV1, EIF2AK4, ENG, GDF2, KCNK3, KDR, SMAD9, SOX17, and TBX4) were classified as having definitive evidence and 3 genes (ABCC8, GGCX, and TET2) with moderate evidence. Six genes (AQP1, BMP10, FBLN2, KLF2, KLK1, and PDGFD) were classified as having limited evidence for causal effects of variants. TOPBP1 was classified as having no known PAH relationship. Five genes (BMPR1A, BMPR1B, NOTCH3, SMAD1, and SMAD4) were disputed because of a paucity of genetic evidence over time. CONCLUSION We recommend that genetic testing includes all genes with definitive evidence and that caution be taken in the interpretation of variants identified in genes with moderate or limited evidence. Genes with no known evidence for PAH or disputed genes should not be included in genetic testing.
Collapse
Affiliation(s)
- Carrie L Welch
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY
| | - Micheala A Aldred
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University School of Medicine, IN
| | - Srimmitha Balachandar
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University School of Medicine, IN
| | - Dennis Dooijes
- Department of Genetics, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Christina A Eichstaedt
- Center for Pulmonary Hypertension, Thoraxklinik-Heidelberg gGmbH, at Heidelberg University Hospital and Translational Lung Research Center, German Center for Lung Research, Heidelberg, Germany; Laboratory for Molecular Genetic Diagnostics, Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Stefan Gräf
- NIHR BioResource for Translational Research - Rare Diseases, Department of Haemotology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom; Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Arjan C Houweling
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Rajiv D Machado
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom
| | - Divya Pandya
- Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Matina Prapa
- Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom; St. George's University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Memoona Shaukat
- Center for Pulmonary Hypertension, Thoraxklinik-Heidelberg gGmbH, at Heidelberg University Hospital and Translational Lung Research Center, German Center for Lung Research, Heidelberg, Germany; Laboratory for Molecular Genetic Diagnostics, Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Laura Southgate
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom
| | - Jair Tenorio-Castano
- Institute of Medical and Molecular Genetics (INGEMM), Hospital Universitario La Paz, IDiPAZ, Universidad Autonoma de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; ITHACA, European Reference Network, Brussels, Belgium
| | - Wendy K Chung
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY; Department of Medicine, Columbia University Irving Medical Center, New York, NY.
| |
Collapse
|
2
|
Ishida H, Maeda J, Uchida K, Yamagishi H. Unique Pulmonary Hypertensive Vascular Diseases Associated with Heart and Lung Developmental Defects. J Cardiovasc Dev Dis 2023; 10:333. [PMID: 37623346 PMCID: PMC10455332 DOI: 10.3390/jcdd10080333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/10/2023] [Accepted: 08/01/2023] [Indexed: 08/26/2023] Open
Abstract
Although pediatric pulmonary hypertension (PH) shares features and mechanisms with adult PH, there are also some significant differences between the two conditions. Segmental PH is a unique pediatric subtype of PH with unclear and/or multifactorial pathophysiological mechanisms, and is often associated with complex congenital heart disease (CHD), pulmonary atresia with ventricular septal defect, and aortopulmonary collateral arteries. Some cases of complex CHD, associated with a single ventricle after Fontan operation, show pathological changes in the small peripheral pulmonary arteries and pulmonary vascular resistance similar to those observed in pulmonary arterial hypertension (PAH). This condition is termed as the pediatric pulmonary hypertensive vascular disease (PPHVD). Recent advances in genetics have identified the genes responsible for PAH associated with developmental defects of the heart and lungs, such as TBX4 and SOX17. Targeted therapies for PAH have been developed; however, their effects on PH associated with developmental heart and lung defects remain to be established. Real-world data analyses on the anatomy, pathophysiology, genetics, and molecular biology of unique PPHVD cases associated with developmental defects of the heart and lungs, using nationwide and/or international registries, should be conducted in order to improve the treatments and prognosis of patients with these types of pediatric PH.
Collapse
Affiliation(s)
- Hidekazu Ishida
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Osaka, Japan;
| | - Jun Maeda
- Department of Cardiology, Tokyo Metropolitan Children’s Medical Center, 2-8-29 Musashidai, Fuchu 183-8561, Tokyo, Japan;
| | - Keiko Uchida
- Department of Pediatrics, Keio University of Medicine, 35 Shinanomachi, Shinjuku-ku 160-8582, Tokyo, Japan;
- Keio University Health Center, 4-1-1 Hiyoshi, Kohoku-ku, Yokohama 223-8521, Kanagawa, Japan
| | - Hiroyuki Yamagishi
- Department of Pediatrics, Keio University of Medicine, 35 Shinanomachi, Shinjuku-ku 160-8582, Tokyo, Japan;
| |
Collapse
|
3
|
Flanagan FO, Holtz AM, Vargas SO, Genetti CA, Schmitz-Abe K, Casey A, Kennedy JC, Raby BA, Mullen MP, Fishman MP, Agrawal PB. An intronic variant in TBX4 in a single family with variable and severe pulmonary manifestations. NPJ Genom Med 2023; 8:7. [PMID: 36878902 PMCID: PMC9988848 DOI: 10.1038/s41525-023-00350-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 02/09/2023] [Indexed: 03/08/2023] Open
Abstract
A male infant presented at term with neonatal respiratory failure and pulmonary hypertension. His respiratory symptoms improved initially, but he exhibited a biphasic clinical course, re-presenting at 15 months of age with tachypnea, interstitial lung disease, and progressive pulmonary hypertension. We identified an intronic TBX4 gene variant in close proximity to the canonical donor splice site of exon 3 (hg 19; chr17:59543302; c.401 + 3 A > T), also carried by his father who had a typical TBX4-associated skeletal phenotype and mild pulmonary hypertension, and by his deceased sister who died shortly after birth of acinar dysplasia. Analysis of patient-derived cells demonstrated a significant reduction in TBX4 expression resulting from this intronic variant. Our study illustrates the variable expressivity in cardiopulmonary phenotype conferred by TBX4 mutation and the utility of genetic diagnostics in enabling accurate identification and classification of more subtly affected family members.
Collapse
Affiliation(s)
- Frances O Flanagan
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Alexander M Holtz
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Sara O Vargas
- Department of Pathology, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Casie A Genetti
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, USA
| | - Klaus Schmitz-Abe
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, USA
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Alicia Casey
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - John C Kennedy
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Benjamin A Raby
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Mary P Mullen
- Department of Cardiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA.
| | - Martha P Fishman
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA
| | - Pankaj B Agrawal
- Division of Genetics & Genomics, Department of Pediatrics, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA.
- Department of Pathology, Boston Children's Hospital, and Harvard Medical School, Boston, MA, USA.
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, USA.
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
4
|
Taha F, Southgate L. Molecular genetics of pulmonary hypertension in children. Curr Opin Genet Dev 2022; 75:101936. [PMID: 35772304 PMCID: PMC9763127 DOI: 10.1016/j.gde.2022.101936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/20/2022] [Accepted: 05/19/2022] [Indexed: 12/24/2022]
Abstract
Until recently, the molecular aetiology of paediatric pulmonary hypertension (PH) was relatively poorly understood. While the TGF-β/BMP pathway was recognised as central to disease progression, genetic analyses in children were largely confined to targeted screening of risk genes in small cohorts, with clinical management extrapolated from adult data. In recent years, next-generation sequencing has highlighted notable differences in the genetic architecture underlying childhood-onset cases, with a higher genetic burden in children partly explained by comorbidities such as congenital heart disease. Here, we review recent genetic advances in paediatric PH and highlight important risk factors such as dysregulation of the transcription factors SOX17 and TBX4. Given the poorer prognosis in paediatric cases, molecular diagnosis offers a vital tool to enhance clinical care of children with PH.
Collapse
Affiliation(s)
- Fatima Taha
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | - Laura Southgate
- Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK.
| |
Collapse
|
5
|
Genetic and functional analyses of TBX4 reveal novel mechanisms underlying pulmonary arterial hypertension. J Mol Cell Cardiol 2022; 171:105-116. [PMID: 35914404 DOI: 10.1016/j.yjmcc.2022.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/29/2022] [Accepted: 07/07/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a fatal disease, with approximately 10% of cases associated with genetic variants. Recent genetic studies have reported pathogenic variants in the TBX4 gene in patients with PAH, especially in patients with childhood-onset of the disease, but the pathogenesis of PAH caused by TBX4 variant has not been fully uncovered. METHODS We analysed the TBX4 gene in 75 Japanese patients with sporadic or familial PAH using a PCR-based bidirectional sequencing method. Detected variants were evaluated using in silico analyses as well as in vitro analyses including luciferase assay, immunocytochemistry and chromatin immunoprecipitation (ChIP) whether they have altered function. We also analysed the function of TBX4 using mouse embryonic lung explants with inhibition of Tbx4 expression. RESULTS Putative pathogenic variants were detected in three cases (4.0%). Our in vitro functional analyses revealed that TBX4 directly regulates the transcriptional activity of fibroblast growth factor 10 (FGF10), whereas the identified TBX4 variant proteins failed to activate the FGF10 gene because of disruption of nuclear localisation signal or poor DNA-binding affinity. Furthermore, ex vivo inhibition of Tbx4 resulted in insufficiency of lung morphogenesis along with specific downregulation of Tie2 and Kruppel-like factor 4 expression. CONCLUSION Our results implicate variants in TBX4 as a genetic cause of PAH in a subset of the Japanese population. Variants in TBX4 may lead to PAH through insufficient lung morphogenesis by disrupting the TBX4-mediated direct regulation of FGF10 signalling and pulmonary vascular endothelial dysfunction involving PAH-related molecules.
Collapse
|