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Ackerman C, Locke A, Feingold E, Reshey B, Espana K, Thusberg J, Mooney S, Bean L, Dooley K, Cua C, Reeves R, Sherman S, Maslen C. An excess of deleterious variants in VEGF-A pathway genes in Down-syndrome-associated atrioventricular septal defects. Am J Hum Genet 2012; 91:646-59. [PMID: 23040494 PMCID: PMC3484504 DOI: 10.1016/j.ajhg.2012.08.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 06/12/2012] [Accepted: 08/17/2012] [Indexed: 12/20/2022] Open
Abstract
About half of people with trisomy 21 have a congenital heart defect (CHD), whereas the remainder have a structurally normal heart, demonstrating that trisomy 21 is a significant risk factor but is not causal for abnormal heart development. Atrioventricular septal defects (AVSD) are the most commonly occurring heart defects in Down syndrome (DS), and ∼65% of all AVSD is associated with DS. We used a candidate-gene approach among individuals with DS and complete AVSD (cases = 141) and DS with no CHD (controls = 141) to determine whether rare genetic variants in genes involved in atrioventricular valvuloseptal morphogenesis contribute to AVSD in this sensitized population. We found a significant excess (p < 0.0001) of variants predicted to be deleterious in cases compared to controls. At the most stringent level of filtering, we found potentially damaging variants in nearly 20% of cases but fewer than 3% of controls. The variants with the highest probability of being damaging in cases only were found in six genes: COL6A1, COL6A2, CRELD1, FBLN2, FRZB, and GATA5. Several of the case-specific variants were recurrent in unrelated individuals, occurring in 10% of cases studied. No variants with an equal probability of being damaging were found in controls, demonstrating a highly specific association with AVSD. Of note, all of these genes are in the VEGF-A pathway, even though the candidate genes analyzed in this study represented numerous biochemical and developmental pathways, suggesting that rare variants in the VEGF-A pathway might contribute to the genetic underpinnings of AVSD in humans.
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Affiliation(s)
- Christine Ackerman
- Division of Cardiovascular Medicine and the Heart Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Adam E. Locke
- Department of Human Genetics, Emory University, Atlanta, GA 30033, USA
| | - Eleanor Feingold
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Benjamin Reshey
- Division of Cardiovascular Medicine and the Heart Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Karina Espana
- Division of Cardiovascular Medicine and the Heart Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | | | - Sean Mooney
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Lora J.H. Bean
- Department of Human Genetics, Emory University, Atlanta, GA 30033, USA
| | - Kenneth J. Dooley
- Sibley Heart Center Cardiology and Division of Pediatric Cardiology, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30033, USA
| | - Clifford L. Cua
- Heart Center, Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Roger H. Reeves
- Department of Physiology and the Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Cheryl L. Maslen
- Division of Cardiovascular Medicine and the Heart Research Center, Oregon Health & Science University, Portland, OR 97239, USA
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Patel SS, Mahoney LT, Burns TL. Is a shorter atrioventricular septal length an intermediate phenotype in the spectrum of nonsyndromic atrioventricular septal defects? J Am Soc Echocardiogr 2012; 25:782-9. [PMID: 22542274 DOI: 10.1016/j.echo.2012.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Indexed: 10/28/2022]
Abstract
BACKGROUND Atrioventricular septal defects (AVSDs) account for 7% of all congenital cardiovascular malformations. The atrioventricular septum (AVS) is the portion of the septal tissue that separates the right atrium from the left ventricle; deficiency of the AVS contributes to the AVSD phenotype. A study of case and control families was performed to identify whether an intermediate phenotype consisting of a shortened AVS existed in relatives of children with AVSDs. METHODS AVS length (AVSL) was measured on the echocardiograms of clinically unaffected parents and siblings from families that were identified through children with nonsyndromic AVSDs and in families with no histories of congenital heart disease. RESULTS No significant differences were seen between case and control family members in terms of gender, age, weight, and height. AVSLs were significantly shorter in case parents compared with control parents. Similar findings were noted within the sibling groups. There was significant evidence for two-component distributions in the case parent, case sibling, and control sibling groups after standardizing AVSL for age and body surface area. Heritability of AVSL standardized for age and body surface area was 0.82 and 0.71 in nonsyndromic case and control families, respectively. CONCLUSIONS Evidence for two-component distributions from the analysis of AVSL standardized for age and body surface area for case parents and case siblings suggests the presence of an intermediate phenotype for nonsyndromic AVSD. The high heritability in the control families suggests that there may be polygenic involvement in the determination of AVSL. Broadening the definition of AVSD to include those with shortened AVSL may increase the power of genetic association and mapping studies to identify susceptibility genes for AVSD.
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Affiliation(s)
- Sonali S Patel
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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