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Bene Watts S, Gauthier B, Erickson AC, Morrison J, Sebastian M, Gillman L, McIntosh S, Ens C, Sherwin E, McCormick R, Sanatani S, Arbour L. A mild phenotype associated with KCNQ1 p.V205M mediated long QT syndrome in First Nations children of Northern British Columbia: effect of additional variants and considerations for management. Front Pediatr 2024; 12:1394105. [PMID: 38884101 PMCID: PMC11176454 DOI: 10.3389/fped.2024.1394105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
Introduction Congenital Long QT Syndrome (LQTS) is common in a First Nations community in Northern British Columbia due to the founder variant KCNQ1 p.V205M. Although well characterized molecularly and clinically in adults, no data have been previously reported on the pediatric population. The phenotype in adults has been shown to be modified by a splice site variant in KCNQ1 (p.L353L). The CPT1A p.P479L metabolic variant, also common in Northern Indigenous populations, is associated with hypoglycemia and infant death. Since hypoglycemia can affect the corrected QT interval (QTc) and may confer risk for seizures (also associated with LQTS), we sought to determine the effect of all three variants on the LQTS phenotype in children within our First Nations cohort. Methods As part of a larger study assessing those with LQTS and their relatives in a Northern BC First Nation, we assessed those entering the study from birth to age 18 years. We compared the corrected peak QTc and potential cardiac events (syncope/seizures) of 186 children from birth to 18 years, with and without the KCNQ1 (p.V205M and p.L353L) and CPT1A variants, alone and in combination. Linear and logistic regression and student t-tests were applied as appropriate. Results Only the KCNQ1 p.V205M variant conferred a significant increase in peak QTc 23.8 ms (p < 0.001) above baseline, with females increased by 30.1 ms (p < 0.001) and males by 18.9 ms (p < 0.01). There was no evidence of interaction effects with the other two variants studied. Although the p.V205M variant was not significantly associated with syncope/seizures, the odds of having a seizure/syncope were significantly increased for those homozygous for CPT1A p.P479L compared to homozygous wild type (Odds Ratio [OR]3.0 [95% confidence interval (CI) 1.2-7.7]; p = 0.019). Conclusion While the KCNQ1 p.V205M variant prolongs the peak QTc, especially in females, the CPT1A p.P479L variant is more strongly associated with loss of consciousness events. These findings suggest that effect of the KCNQ1 p.V205M variant is mild in this cohort, which may have implications for standard management. Our findings also suggest the CPT1A p.P479L variant is a risk factor for seizures and possibly syncope, which may mimic a long QT phenotype.
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Affiliation(s)
- Simona Bene Watts
- Island Medical Program, University of British Columbia, Victoria, BC, Canada
| | - Barbara Gauthier
- Epidemiology and Surveillance Unit, Interior Health Authority, Kelowna, BC, Canada
| | | | | | | | - Lawrence Gillman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sarah McIntosh
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Connie Ens
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Elizabeth Sherwin
- Department of Pediatrics, Children's National Hospital, Washington, DC, United States
| | - Rod McCormick
- Department of Education and Social Work, Thompson Rivers University, Kamloops, BC, Canada
| | - Shubhayan Sanatani
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Laura Arbour
- Island Medical Program, University of British Columbia, Victoria, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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2
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Marchand M, Erickson AC, Gillman L, Haywood R, Morrison J, Jaworsky D, Drouin O, Laksman Z, Krahn AD, Arbour L. The Impact of Chronic Disease on the Corrected QT (QTc) Value in Women in a British Columbia First Nations Population. Can J Cardiol 2024; 40:89-97. [PMID: 37852605 DOI: 10.1016/j.cjca.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 09/27/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Indigenous women have higher rates of chronic disease than Indigenous men and non-Indigenous women. Long QT syndrome (LQTS) can be inherited or acquired; the latter may occur with chronic disease. A prolonged corrected QT value (QTc) is an independent risk factor for ventricular arrhythmias and sudden death, but few studies have quantified the impact of chronic disease on the QTc. We assessed the association between chronic disease and QTc prolongation in a population of First Nations women previously ascertained to study a high rate of inherited LQTS due to a unique genetic (founder) variant in their community. METHODS This substudy focusing on women expands on the original research where patients with clinical features of LQTS and their relatives were assessed for genetic variants discovered to affect the QTc. Medical records were retrospectively reviewed and chronic diseases documented. Using multivariate linear regression, adjusting for the effect of genetic variants, age, and QTc-prolonging medications, we evaluated the association between chronic disease and the QTc. RESULTS In total, 275 women were included. After adjustments, a prolonged QTc was associated with coronary artery disease (26.5 ms, 95% confidence interval [CI] 9.0-44.1 ms; P = 0.003), conduction system disease (26.8 ms, 95% CI 2.2-51.4 ms; P = 0.033), rheumatoid arthritis (28.9 ms, 95% CI 12.7-45.1 ms; P = 0.001), and type 2 diabetes mellitus (17.9 ms, 95% CI 3.6-32.3 ms; P = 0.015). CONCLUSIONS This quantification of the association between chronic disease and QTc prolongation in an Indigenous cohort provides insight into the nongenetic determinants of QTc prolongation. Corroboration in other populations will provide evidence for generalisability of these results.
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Affiliation(s)
- Miles Marchand
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Syilx Okanagan Nation, British Columbia, Canada
| | - Anders C Erickson
- Population and Public Health Division, British Columbia Ministry of Health, Victoria, British Columbia, Canada(‡)
| | - Lawrence Gillman
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada
| | - Rachel Haywood
- Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada
| | - Julie Morrison
- Community Member, Gitxsan Nation, British Columbia, Canada
| | - Denise Jaworsky
- Northern Health Authority, Terrace, British Columbia, Canada; Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Olivier Drouin
- Northern Health Authority, Terrace, British Columbia, Canada
| | - Zachary Laksman
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada.
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3
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Sieliwonczyk E, Alaerts M, Simons E, Snyders D, Nijak A, Vandendriessche B, Schepers D, Akdeniz D, Van Craenenbroeck E, Knaepen K, Rabaut L, Heidbuchel H, Van Laer L, Saenen J, Labro AJ, Loeys B. Clinical and functional characterisation of a recurrent KCNQ1 variant in the Belgian population. Orphanet J Rare Dis 2023; 18:23. [PMID: 36721196 PMCID: PMC9887867 DOI: 10.1186/s13023-023-02618-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 01/15/2023] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The c.1124_1127delTTCA p.(Ile375Argfs*43) pathogenic variant is the most frequently identified molecular defect in the KCNQ1 gene in the cardiogenetics clinic of the Antwerp University Hospital. This variant was observed in nine families presenting with either Jervell-Lange-Nielsen syndrome or long QT syndrome (LQTS). Here, we report on the molecular, clinical and functional characterization of the KCNQ1 c.1124_1127delTTCA variant. RESULTS Forty-one heterozygous variant harboring individuals demonstrated a predominantly mild clinical and electrophysiological phenotype, compared to individuals harboring other KCNQ1 pathogenic variants (5% symptomatic before 40 years of age, compared to 24% and 29% in p.(Tyr111Cys) and p.(Ala341Val) variant carriers, respectively, 33% with QTc ≤ 440 ms compared to 10% in p.(Tyr111Cys) and p.(Ala341Val) variant carriers). The LQTS phenotype was most comparable to that observed for the Swedish p.(Arg518*) founder mutation (7% symptomatic at any age, compared to 17% in p.(Arg518*) variant carriers, 33% with QTc ≤ 440 ms compared to 16% in p.(Arg518*) variant carriers). Surprisingly, short tandem repeat analysis did not reveal a common haplotype for all families. One KCNQ1 c.1124_1127delTTCA harboring patient was diagnosed with Brugada syndrome (BrS). The hypothesis of a LQTS/BrS overlap syndrome was supported by electrophysiological evidence for both loss-of-function and gain-of-function (acceleration of channel kinetics) in a heterologous expression system. However, BrS phenotypes were not identified in other affected individuals and allelic KCNQ1 expression testing in patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) showed nonsense mediated decay of the c.1124_1127delTTCA allele. CONCLUSIONS The c.1124_1127delTTCA frameshift variant shows a high prevalence in our region, despite not being confirmed as a founder mutation. This variant leads to a mild LQTS phenotype in the heterozygous state. Despite initial evidence for a gain-of-function effect based on in vitro electrophysiological assessment in CHO cells and expression of the KCNQ1 c.1124_1127delTTCA allele in patient blood cells, additional testing in iPSC-CMs showed lack of expression of the mutant allele. This suggests haploinsufficiency as the pathogenic mechanism. Nonetheless, as inter-individual differences in allele expression in (iPSC-) cardiomyocytes have not been assessed, a modifying effect on the BrS phenotype through potassium current modulation cannot be excluded.
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Affiliation(s)
- Ewa Sieliwonczyk
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium. .,Medical Genetics (MEDGEN), GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
| | - Maaike Alaerts
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Medical Genetics (MEDGEN), GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Eline Simons
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Dirk Snyders
- grid.5284.b0000 0001 0790 3681Experimental Neurobiology Unit, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Aleksandra Nijak
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Bert Vandendriessche
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Dorien Schepers
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Medical Genetics (MEDGEN), GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Experimental Neurobiology Unit, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Dogan Akdeniz
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Emeline Van Craenenbroeck
- grid.5284.b0000 0001 0790 3681Department of Cardiology, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Cardiovascular Research, GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Katleen Knaepen
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Laura Rabaut
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Hein Heidbuchel
- grid.5284.b0000 0001 0790 3681Department of Cardiology, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Cardiovascular Research, GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Lut Van Laer
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Medical Genetics (MEDGEN), GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Johan Saenen
- grid.5284.b0000 0001 0790 3681Department of Cardiology, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Cardiovascular Research, GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Alain J. Labro
- grid.5284.b0000 0001 0790 3681Experimental Neurobiology Unit, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium ,grid.5342.00000 0001 2069 7798Department of Basic and Applied Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Bart Loeys
- grid.5284.b0000 0001 0790 3681Center of Medical Genetics, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium ,grid.5284.b0000 0001 0790 3681Medical Genetics (MEDGEN), GENCOR, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
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Streeten EA, See VY, Jeng LBJ, Maloney KA, Lynch M, Glazer AM, Yang T, Roden D, Pollin TI, Daue M, Ryan KA, Van Hout C, Gosalia N, Gonzaga-Jauregui C, Economides A, Perry JA, O'Connell J, Beitelshees A, Palmer K, Mitchell BD, Shuldiner AR. KCNQ1 and Long QT Syndrome in 1/45 Amish: The Road From Identification to Implementation of Culturally Appropriate Precision Medicine. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 13:e003133. [PMID: 33141630 PMCID: PMC7748050 DOI: 10.1161/circgen.120.003133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. In population-based research exome sequencing, the path from variant discovery to return of results is not well established. Variants discovered by research exome sequencing have the potential to improve population health.
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Affiliation(s)
- Elizabeth A Streeten
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Vincent Y See
- Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine.,Division of Cardiolovascular Medicine (V.Y.S., T.I.P., K.P.), University of Maryland School of Medicine
| | - Linda B J Jeng
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Kristin A Maloney
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Megan Lynch
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Andrew M Glazer
- Division of Clinical Pharmacology, Department of Medicine (A.M.G., T.Y., D.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Tao Yang
- Division of Clinical Pharmacology, Department of Medicine (A.M.G., T.Y., D.R.), Vanderbilt University Medical Center, Nashville, TN.,Department of Pharmacology (T.Y., D.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Dan Roden
- Division of Clinical Pharmacology, Department of Medicine (A.M.G., T.Y., D.R.), Vanderbilt University Medical Center, Nashville, TN.,Department of Pharmacology (T.Y., D.R.), Vanderbilt University Medical Center, Nashville, TN.,Biomedical Informatics (D.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Toni I Pollin
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine.,Division of Cardiolovascular Medicine (V.Y.S., T.I.P., K.P.), University of Maryland School of Medicine
| | - Melanie Daue
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Kathleen A Ryan
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Cristopher Van Hout
- Regeneron Genetics Center LLC, Tarrytown, NY (C.V.H., N.G., C.G.-J., A.E., A.R.S.)
| | - Nehal Gosalia
- Regeneron Genetics Center LLC, Tarrytown, NY (C.V.H., N.G., C.G.-J., A.E., A.R.S.)
| | | | - Aris Economides
- Regeneron Genetics Center LLC, Tarrytown, NY (C.V.H., N.G., C.G.-J., A.E., A.R.S.)
| | - James A Perry
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Jeffrey O'Connell
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Amber Beitelshees
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine
| | - Kathleen Palmer
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Division of Cardiolovascular Medicine (V.Y.S., T.I.P., K.P.), University of Maryland School of Medicine
| | - Braxton D Mitchell
- Program for Personalized and Genomic Medicine (E.A.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., K.P., B.D.M.), University of Maryland School of Medicine.,Department of Medicine (E.A.S., V.Y.S., L.B.J.J., K.A.M., M.L., T.I.P., M.D., K.A.R., J.A.P., J.O., A.B., B.D.M.), University of Maryland School of Medicine.,Baltimore Veterans Administration Medical Center Geriatrics Research and Education Clinical Center, Baltimore, MD (B.D.M.)
| | - Alan R Shuldiner
- Regeneron Genetics Center LLC, Tarrytown, NY (C.V.H., N.G., C.G.-J., A.E., A.R.S.)
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A computational model of induced pluripotent stem-cell derived cardiomyocytes for high throughput risk stratification of KCNQ1 genetic variants. PLoS Comput Biol 2020; 16:e1008109. [PMID: 32797034 PMCID: PMC7449496 DOI: 10.1371/journal.pcbi.1008109] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/26/2020] [Accepted: 06/30/2020] [Indexed: 01/01/2023] Open
Abstract
In the last decade, there has been tremendous progress in identifying genetic anomalies linked to clinical disease. New experimental platforms have connected genetic variants to mechanisms underlying disruption of cellular and organ behavior and the emergence of proarrhythmic cardiac phenotypes. The development of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) signifies an important advance in the study of genetic disease in a patient-specific context. However, considerable limitations of iPSC-CM technologies have not been addressed: 1) phenotypic variability in apparently identical genotype perturbations, 2) low-throughput electrophysiological measurements, and 3) an immature phenotype which may impact translation to adult cardiac response. We have developed a computational approach intended to address these problems. We applied our recent iPSC-CM computational model to predict the proarrhythmic risk of 40 KCNQ1 genetic variants. An IKs computational model was fit to experimental data for each mutation, and the impact of each mutation was simulated in a population of iPSC-CM models. Using a test set of 15 KCNQ1 mutations with known clinical long QT phenotypes, we developed a method to stratify the effects of KCNQ1 mutations based on proarrhythmic markers. We utilized this method to predict the severity of the remaining 25 KCNQ1 mutations with unknown clinical significance. Tremendous phenotypic variability was observed in the iPSC-CM model population following mutant perturbations. A key novelty is our reporting of the impact of individual KCNQ1 mutant models on adult ventricular cardiomyocyte electrophysiology, allowing for prediction of mutant impact across the continuum of aging. This serves as a first step toward translating predicted response in the iPSC-CM model to predicted response of the adult ventricular myocyte given the same genetic mutation. As a whole, this study presents a new computational framework that serves as a high throughput method to evaluate risk of genetic mutations based-on proarrhythmic behavior in phenotypically variable populations. In the last decade, there has been tremendous progress in identifying genetic mutations linked to clinical diseases, such as cardiac arrhythmia. Many experimental platforms have been developed to study this link, including induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). IPSC-CMs are patient-derived cardiac cells which allow for the study of genetic variants within a patient-specific context. However, experimentally iPSC-CMs have certain limitations, including: (1) they exhibit variability in behavior within cells that are apparently genetically identical, and (2) they are immature compared to adult cardiac cells. In our study, we have developed a computational approach to model 40 genetic variants in the KCNQ1 gene and predict the proarrhythmic risk of each variant. To do this, we modeled the ionic current determined by KCNQ1, IKs, to fit experimental data for each mutation. We then simulated the impact of each mutation in a population of iPSC-CMs, incorporating variability across the population. We also simulated each variant in an adult cardiac cell model, providing a link between iPSC-CM response to mutants and adult cardiac cell response to the same mutants. Overall, this study provides a new computational framework to evaluate risk of genetic mutations based-on proarrhythmic behavior diverse populations of iPSC-CM models.
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6
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Huisman LA, Bene Watts S, Arbour L, McCormick R. Understanding the personal and community impact of long QT syndrome: A perspective from Gitxsan women. J Genet Couns 2020; 29:562-573. [PMID: 32329955 DOI: 10.1002/jgc4.1255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/10/2022]
Abstract
There is a disproportionately high rate of hereditary long QT syndrome (LQTS) in Northern British Columbia First Nations people, largely due to a novel missense variant in KCNQ1 (p.V205M). The variant has been previously described predisposing those affected to syncope, arrhythmia, and sudden death. Although the biological aspects of LQTS have been explored extensively, less research has been done into the impact of living with a genetic variant that predisposes one to sudden death, and no previous studies have provided cultural insights from a First Nations community. The goal of this study was to explore what facilitates and hinders resiliency and coping for those living with LQTS. Participants were invited to partake in their choice of one-to-one interviews, Photovoice, and Talking Circles. This paper presents the findings from the interview portion of the study. Interviews were recorded, transcribed, and analyzed qualitatively using the systematic text condensation method. Ten women shared their personal experiences of living with LQTS through individual interviews. Half of the women had tested positive for the p.V205M variant, and the other half were awaiting results. In general, learning about a LQTS diagnosis was perceived as traumatic, with gradual acceptance that led to coping. The main factors found to facilitate resiliency and coping were positive family relationships, spirituality, and knowledge about LQTS. The main factors found to hinder resiliency and coping were a poor understanding of the biological or clinical aspects of LQTS, conflicting medical advice (especially regarding physical activity) and LQTS not being taken seriously by social contacts and healthcare providers. It appears that learning to live with LQTS is an ongoing process, requiring balance and interconnectedness between all aspects of well-being.
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Affiliation(s)
- Lee-Anna Huisman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Simona Bene Watts
- Interdisciplinary Studies, University of Victoria, Victoria, BC, Canada
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Rod McCormick
- Department of Education, Thompson River University, Kamloops, BC, Canada
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7
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Caron NR, Chongo M, Hudson M, Arbour L, Wasserman WW, Robertson S, Correard S, Wilcox P. Indigenous Genomic Databases: Pragmatic Considerations and Cultural Contexts. Front Public Health 2020; 8:111. [PMID: 32391301 PMCID: PMC7193324 DOI: 10.3389/fpubh.2020.00111] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/19/2020] [Indexed: 12/01/2022] Open
Abstract
The potential to grow genomic knowledge and harness the subsequent clinical benefits has escalated the building of background variant databases (BVDs) for genetic diagnosis across the globe. Alongside the upsurge of this precision medicine, potential benefits have been highlighted for both rare genetic conditions and other diagnoses. However, with the ever-present “genomic divide,” Indigenous peoples globally have valid concerns as they endure comparatively greater health disparities but stand to benefit the least from these novel scientific discoveries and progress in healthcare. The paucity of Indigenous healthcare providers and researchers in these fields contributes to this genomic divide both in access to, and availability of culturally safe, relevant and respectful healthcare using this genetic knowledge. The vital quest to provide equitable clinical research, and provision and use of genomic services and technologies provides a strong rationale for building BVDs for Indigenous peoples. Such tools would ground their representation and participation in accompanying genomic health research and benefit acquisition. We describe two, independent but highly similar initiatives–the “Silent Genomes” in Canada and the “Aotearoa Variome” in New Zealand–as exemplars that have had to address the aforementioned issues and work to create Indigenous BVDs with these populations. Taking into account the baseline inequities in genomic medicine for Indigenous populations and the ongoing challenges of implementing genomic research with Indigenous communities, we provide a rationale for multiple changes required that will assure communities represented in BVDs, as well as Indigenous researchers, that their participation will maximize benefits and minimize risk.
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Affiliation(s)
- Nadine Rena Caron
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Genome Sciences Center, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - Meck Chongo
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Northern Medical Program, University of Northern British Columbia Canada, Prince George, BC, Canada
| | - Maui Hudson
- Faculty of Māori and Indigenous Studies, University of Waikato, Hamilton, New Zealand
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Wyeth W Wasserman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Stephen Robertson
- Department of Mathematics & Statistics, University of Otago, Dunedin, New Zealand
| | - Solenne Correard
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Phillip Wilcox
- Department of Mathematics & Statistics, University of Otago, Dunedin, New Zealand
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Tung M, Van Petegem F, Lauson S, Collier A, Hodgkinson K, Fernandez B, Connors S, Leather R, Sanatani S, Arbour L. Cardiac arrest in a mother and daughter and the identification of a novel
RYR2
variant, predisposing to low penetrant catecholaminergic polymorphic ventricular tachycardia in a four‐generation Canadian family. Mol Genet Genomic Med 2020; 8:e1151. [PMID: 31994352 PMCID: PMC7196448 DOI: 10.1002/mgg3.1151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/11/2020] [Indexed: 01/30/2023] Open
Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited arrhythmia syndrome characterized by adrenergically driven ventricular arrhythmia predominantly caused by pathogenic variants in the cardiac ryanodine receptor (RyR2). We describe a novel variant associated with cardiac arrest in a mother and daughter. Methods Initial sequencing of the RYR2 gene identified a novel variant (c.527G > T, p.R176L) in the index case (the mother), and her daughter. Structural analysis demonstrated the variant was located within the N‐terminal domain of RyR2, likely leading to a gain‐of‐function effect facilitating enhanced calcium ion release. Four generation cascade genetic and clinical screening was carried out. Results Thirty‐eight p.R176L variant carriers were identified of 94 family members with genetic testing, and 108 family members had clinical evaluations. Twelve carriers were symptomatic with previous syncope and 2 additional survivors of cardiac arrest were identified. Thirty‐two had clinical features suggestive of CPVT. Of 52 noncarriers, 11 had experienced previous syncope with none exhibiting any clinical features of CPVT. A documented arrhythmic event rate of 2.89/1000 person‐years across all carriers was calculated. Conclusion The substantial variability in phenotype and the lower than previously reported penetrance is illustrative of the importance of exploring family variants beyond first‐degree relatives.
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Affiliation(s)
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology University of British Columbia Vancouver BC Canada
| | - Samantha Lauson
- Division of Medical Genetics Island Health Victoria BC Canada
| | - Ashley Collier
- Provincial Medical Genetics Program Eastern Health St. John's NL Canada
| | - Kathy Hodgkinson
- Clinical Epidemiology and Genetics, Faculty of Medicine Memorial University of Newfoundland St John's NL Canada
| | - Bridget Fernandez
- Provincial Medical Genetics Program Eastern Health St. John's NL Canada
- Discipline of Genetics, Faculty of Medicine Memorial University of Newfoundland St John’s NL Canada
| | - Sean Connors
- Division of Cardiology Faculty of Medicine Memorial University of Newfoundland St John's NL Canada
| | | | - Shubhayan Sanatani
- Division of Cardiology Department of Pediatrics University of British Columbia Vancouver BC Canada
| | - Laura Arbour
- Division of Medical Genetics Island Health Victoria BC Canada
- Department of Medical Genetics University of British Columbia Vancouver BC Canada
- Division of Medical Sciences University of Victoria Victoria BC Canada
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9
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Wang Z, Wang L, Liu W, Hu D, Gao Y, Ge Q, Liu X, Li L, Wang Y, Wang S, Li C. Pathogenic mechanism and gene correction for LQTS-causing double mutations in KCNQ1 using a pluripotent stem cell model. Stem Cell Res 2019; 38:101483. [PMID: 31226583 DOI: 10.1016/j.scr.2019.101483] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/04/2019] [Accepted: 06/10/2019] [Indexed: 02/06/2023] Open
Abstract
AIMS To establish a KCNQ1 mutant-specific induced pluripotent stem cell (iPSC) model of a Chinese inherited long QT syndrome (LQTS) patient and to explore the pathogenesis of KCNQ1 mutations. METHODS AND RESULTS (1) Two patient-specific iPSC lines from the proband were obtained. (2) The experiments produced spontaneously beating cardiomyocytes (CMs) from patient iPSCs. Splicing mutation c. 605-2A > G in iPSC-derived cardiomyocytes (iPSC-CMs) resulted in the skipping of exon 4, exons 3-4, or exons 3-6 in KCNQ1 transcription what was observed in the patient's peripheral leukocytes. (3) Action potential duration (APD) at 50% and 90% repolarization (APD50 and APD90) of the patient's iPSC-derived ventricular-like-CMs was significantly longer than that of the control. Moreover, early after depolarization (EAD) and coupled beats were observed only in L1-iPSC-CMs. (4) A c.815G > A corrected iPSC line was obtained by using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein 9 (Cas9) system. CONCLUSION (1) Cardiomyocytes with spontaneous pulsation were successfully differentiated from LQTS patient-specific iPSC lines. (2) For KCNQ1 splicing mutations, there is a chance that splicing patterns in peripheral leukocytes are similar to that in patient iPSC-CMs. (3) The truncated KCNQ1 proteins induced by such splicing mutation might cause Iks decrease, which in turn produced APD prolongation and triggered activities. (4) Our data showed that CRISPR-Cas9 system could be used to rescue the LQTS-related mutations.
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Affiliation(s)
- Zhen Wang
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Lipeng Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, China
| | - Wenling Liu
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Dayi Hu
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Yuanfeng Gao
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Qing Ge
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Xin Liu
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Lei Li
- Heart Center, Peking University People's Hospital, Beijing, China
| | - Yangming Wang
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China.
| | - Shiqiang Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, China.
| | - Cuilan Li
- Heart Center, Peking University People's Hospital, Beijing, China.
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10
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Understanding human DNA variants affecting pre-mRNA splicing in the NGS era. ADVANCES IN GENETICS 2019; 103:39-90. [PMID: 30904096 DOI: 10.1016/bs.adgen.2018.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pre-mRNA splicing, an essential step in eukaryotic gene expression, relies on recognition of short sequences on the primary transcript intron ends and takes place along transcription by RNA polymerase II. Exonic and intronic auxiliary elements may modify the strength of exon definition and intron recognition. Splicing DNA variants (SV) have been associated with human genetic diseases at canonical intron sites, as well as exonic substitutions putatively classified as nonsense, missense or synonymous variants. Their effects on mRNA may be modulated by cryptic splice sites associated to the SV allele, comprehending exon skipping or shortening, and partial or complete intron retention. As splicing mRNA outputs result from combinatorial effects of both intrinsic and extrinsic factors, in vitro functional assays supported by computational analyses are recommended to assist SV pathogenicity assessment for human Mendelian inheritance diseases. The increasing use of next-generating sequencing (NGS) targeting full genomic gene sequence has raised awareness of the relevance of deep intronic SV in genetic diseases and inclusion of pseudo-exons into mRNA. Finally, we take advantage of recent advances in sequencing and computational technologies to analyze alternative splicing in cancer. We explore the Catalog of Somatic Mutations in Cancer (COSMIC) to describe the proportion of splice-site mutations in cis and trans regulatory elements. Genomic data from large cohorts of different cancer types are increasingly available, in addition to repositories of normal and somatic genetic variations. These are likely to bring new insights to understanding the genetic control of alternative splicing by mapping splicing quantitative trait loci in tumors.
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11
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Crotti L, Ghidoni A, Dagradi F. Genetics of Adult and Fetal Forms of Long QT Syndrome. GENETIC CAUSES OF CARDIAC DISEASE 2019. [DOI: 10.1007/978-3-030-27371-2_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Balestrini S, Sisodiya SM. Personalized treatment in the epilepsies: challenges and opportunities. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2018. [DOI: 10.1080/23808993.2018.1486189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, and Epilepsy Society, Chalfont-St-Peter, Bucks, United Kingdom
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, and Epilepsy Society, Chalfont-St-Peter, Bucks, United Kingdom
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13
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Symonds JD, Zuberi SM. Genetics update: Monogenetics, polygene disorders and the quest for modifying genes. Neuropharmacology 2017; 132:3-19. [PMID: 29037745 DOI: 10.1016/j.neuropharm.2017.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/19/2022]
Abstract
The genetic channelopathies are a broad collection of diseases. Many ion channel genes demonstrate wide phenotypic pleiotropy, but nonetheless concerted efforts have been made to characterise genotype-phenotype relationships. In this review we give an overview of the factors that influence genotype-phenotype relationships across this group of diseases as a whole, using specific individual channelopathies as examples. We suggest reasons for the limitations observed in these relationships. We discuss the role of ion channel variation in polygenic disease and highlight research that has contributed to unravelling the complex aetiological nature of these conditions. We focus specifically on the quest for modifying genes in inherited channelopathies, using the voltage-gated sodium channels as an example. Epilepsy related to genetic channelopathy is one area in which precision medicine is showing promise. We will discuss the successes and limitations of precision medicine in these conditions. This article is part of the Special Issue entitled 'Channelopathies.'
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Affiliation(s)
- Joseph D Symonds
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
| | - Sameer M Zuberi
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK.
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14
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Symonds JD, Zuberi SM. WITHDRAWN: Genetics update: Monogenetics, polygene disorders and the quest for modifying genes. Neuropharmacology 2017:S0028-3908(17)30347-7. [PMID: 28757052 DOI: 10.1016/j.neuropharm.2017.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 07/17/2017] [Indexed: 11/15/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.neuropharm.2017.10.013. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
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Affiliation(s)
- Joseph D Symonds
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
| | - Sameer M Zuberi
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
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15
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Winbo A, Stattin EL, Westin IM, Norberg A, Persson J, Jensen SM, Rydberg A. Sex is a moderator of the association between NOS1AP sequence variants and QTc in two long QT syndrome founder populations: a pedigree-based measured genotype association analysis. BMC MEDICAL GENETICS 2017; 18:74. [PMID: 28720088 PMCID: PMC5516337 DOI: 10.1186/s12881-017-0435-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 07/06/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Sequence variants in the NOS1AP gene have repeatedly been reported to influence QTc, albeit with moderate effect sizes. In the long QT syndrome (LQTS), this may contribute to the substantial QTc variance seen among carriers of identical pathogenic sequence variants. Here we assess three non-coding NOS1AP sequence variants, chosen for their previously reported strong association with QTc in normal and LQTS populations, for association with QTc in two Swedish LQT1 founder populations. METHODS This study included 312 individuals (58% females) from two LQT1 founder populations, whereof 227 genotype positive segregating either Y111C (n = 148) or R518* (n = 79) pathogenic sequence variants in the KCNQ1 gene, and 85 genotype negatives. All were genotyped for NOS1AP sequence variants rs12143842, rs16847548 and rs4657139, and tested for association with QTc length (effect size presented as mean difference between derived and wildtype, in ms), using a pedigree-based measured genotype association analysis. Mean QTc was obtained by repeated manual measurement (preferably in lead II) by one observer using coded 50 mm/s standard 12-lead ECGs. RESULTS A substantial variance in mean QTc was seen in genotype positives 476 ± 36 ms (Y111C 483 ± 34 ms; R518* 462 ± 34 ms) and genotype negatives 433 ± 24 ms. Female sex was significantly associated with QTc prolongation in all genotype groups (p < 0.001). In a multivariable analysis including the entire study population and adjusted for KCNQ1 genotype, sex and age, NOS1AP sequence variants rs12143842 and rs16847548 (but not rs4657139) were significantly associated with QT prolongation, +18 ms (p = 0.0007) and +17 ms (p = 0.006), respectively. Significant sex-interactions were detected for both sequent variants (interaction term r = 0.892, p < 0.001 and r = 0.944, p < 0.001, respectively). Notably, across the genotype groups, when stratified by sex neither rs12143842 nor rs16847548 were significantly associated with QTc in females (both p = 0.16) while in males, a prolongation of +19 ms and +8 ms (p = 0.002 and p = 0.02) was seen in multivariable analysis, explaining up to 23% of QTc variance in all males. CONCLUSIONS Sex was identified as a moderator of the association between NOS1AP sequence variants and QTc in two LQT1 founder populations. This finding may contribute to QTc sex differences and affect the usefulness of NOS1AP as a marker for clinical risk stratification in LQTS.
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Affiliation(s)
- Annika Winbo
- Department of Clinical Sciences, Pediatrics, Umeå University, 90187, Umeå, Sweden. .,Department of Physiology, University of Auckland, Auckland, New Zealand.
| | - Eva-Lena Stattin
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ida Maria Westin
- Department of Medical Biosciences, Medical and Clinical Genetics, Umeå University, Umeå, 90185, Sweden
| | - Anna Norberg
- Department of Medical Biosciences, Medical and Clinical Genetics, Umeå University, Umeå, 90185, Sweden
| | - Johan Persson
- Department of Clinical Sciences, Pediatrics, Umeå University, 90187, Umeå, Sweden
| | - Steen M Jensen
- Department of Public Health and Clinical Medicine, Heart Centre, Umeå University, Umeå, 90185, Sweden
| | - Annika Rydberg
- Department of Clinical Sciences, Pediatrics, Umeå University, 90187, Umeå, Sweden
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