Sahej Bains1, Steven M Dotzler1, Christian Krijger2, John R Giudicessi3, Dan Ye4, Hennie Bikker5, Ram K Rohatgi6, David J Tester7, J Martijn Bos7, Arthur A M Wilde8, Michael J Ackerman9. 1. Medical Scientist Training Program, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota. 2. Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands. 3. Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota. 4. Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota. 5. Department of Human Genetics, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands. 6. Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota. 7. Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota. 8. Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Cardiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands. 9. Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota; Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota. Electronic address: ackerman.michael@mayo.edu.
Abstract
BACKGROUND: Pathogenic/likely pathogenic (P/LP) variants in the KCNQ1-encoded Kv7.1 potassium channel cause type 1 long QT syndrome (LQT1). Despite the revamped 2015 American College of Medical Genetics (ACMG) variant interpretation guidelines, the burden of KCNQ1 variants of uncertain significance (VUS) in patients with LQTS remains ∼30%. OBJECTIVE: The purpose of this study was to determine whether a phenotype-enhanced (PE) variant classification approach could reduce the VUS burden in LQTS genetic testing. METHODS: Retrospective analysis was performed on 79 KCNQ1 missense variants in 356 patients from Mayo Clinic and an independent cohort of 42 variants in 225 patients from Amsterdam University Medical Center (UMC). Each variant was classified initially using the ACMG guidelines and then readjudicated using a PE-ACMG framework that incorporated the LQTS clinical diagnostic Schwartz score plus 4 "LQT1-defining features": broad-based/slow upstroke T waves, syncope/seizure during exertion, swimming-associated events, and a maladaptive LQT1 treadmill stress test. RESULTS: According to the ACMG guidelines, Mayo Clinic variants were classified as follows: 17 of 79 P variants (22%), 34 of 79 LP variants (43%), and 28 of 79 VUS (35%). Similarly, for Amsterdam UMC, the variant distribution was 9 of 42 P variants (22%), 14 of 42 LP variants (33%), and 19 of 42 variants VUS (45%). After PE-ACMG readjudication, the total VUS burden decreased significantly from 28 (35%) to 13 (16%) (P = .0007) for Mayo Clinic and from 19 (45%) to 12 (29%) (P = .02) for Amsterdam UMC. CONCLUSION: Phenotype-guided variant adjudication decreased significantly the VUS burden of LQT1 case-derived KCNQ1 missense variants in 2 independent cohorts. This study demonstrates the value of incorporating LQT1-specific phenotype/clinical data to aid in the interpretation of KCNQ1 missense variants identified during genetic testing for LQTS.
BACKGROUND: Pathogenic/likely pathogenic (P/LP) variants in the KCNQ1-encoded Kv7.1 potassium channel cause type 1 long QT syndrome (LQT1). Despite the revamped 2015 American College of Medical Genetics (ACMG) variant interpretation guidelines, the burden of KCNQ1 variants of uncertain significance (VUS) in patients with LQTS remains ∼30%. OBJECTIVE: The purpose of this study was to determine whether a phenotype-enhanced (PE) variant classification approach could reduce the VUS burden in LQTS genetic testing. METHODS: Retrospective analysis was performed on 79 KCNQ1 missense variants in 356 patients from Mayo Clinic and an independent cohort of 42 variants in 225 patients from Amsterdam University Medical Center (UMC). Each variant was classified initially using the ACMG guidelines and then readjudicated using a PE-ACMG framework that incorporated the LQTS clinical diagnostic Schwartz score plus 4 "LQT1-defining features": broad-based/slow upstroke T waves, syncope/seizure during exertion, swimming-associated events, and a maladaptive LQT1 treadmill stress test. RESULTS: According to the ACMG guidelines, Mayo Clinic variants were classified as follows: 17 of 79 P variants (22%), 34 of 79 LP variants (43%), and 28 of 79 VUS (35%). Similarly, for Amsterdam UMC, the variant distribution was 9 of 42 P variants (22%), 14 of 42 LP variants (33%), and 19 of 42 variants VUS (45%). After PE-ACMG readjudication, the total VUS burden decreased significantly from 28 (35%) to 13 (16%) (P = .0007) for Mayo Clinic and from 19 (45%) to 12 (29%) (P = .02) for Amsterdam UMC. CONCLUSION: Phenotype-guided variant adjudication decreased significantly the VUS burden of LQT1 case-derived KCNQ1 missense variants in 2 independent cohorts. This study demonstrates the value of incorporating LQT1-specific phenotype/clinical data to aid in the interpretation of KCNQ1 missense variants identified during genetic testing for LQTS.
Authors: Arthur A M Wilde; Christopher Semsarian; Manlio F Márquez; Alireza Sepehri Shamloo; Michael J Ackerman; Euan A Ashley; Back Sternick Eduardo; Héctor Barajas-Martinez; Elijah R Behr; Connie R Bezzina; Jeroen Breckpot; Philippe Charron; Priya Chockalingam; Lia Crotti; Michael H Gollob; Steven Lubitz; Naomasa Makita; Seiko Ohno; Martín Ortiz-Genga; Luciana Sacilotto; Eric Schulze-Bahr; Wataru Shimizu; Nona Sotoodehnia; Rafik Tadros; James S Ware; David S Winlaw; Elizabeth S Kaufman; Takeshi Aiba; Andreas Bollmann; Jong-Il Choi; Aarti Dalal; Francisco Darrieux; John Giudicessi; Mariana Guerchicoff; Kui Hong; Andrew D Krahn; Ciorsti Mac Intyre; Judith A Mackall; Lluís Mont; Carlo Napolitano; Pablo Ochoa Juan; Petr Peichl; Alexandre C Pereira; Peter J Schwartz; Jon Skinner; Christoph Stellbrink; Jacob Tfelt-Hansen; Thomas Deneke Journal: J Arrhythm Date: 2022-05-31
Authors: Connie Jiang; Ebony Richardson; Jessica Farr; Adam P Hill; Rizwan Ullah; Brett M Kroncke; Steven M Harrison; Kate L Thomson; Jodie Ingles; Jamie I Vandenberg; Chai-Ann Ng Journal: Am J Hum Genet Date: 2022-06-09 Impact factor: 11.043
Authors: Arthur A M Wilde; Christopher Semsarian; Manlio F Márquez; Alireza Sepehri Shamloo; Michael J Ackerman; Euan A Ashley; Eduardo Back Sternick; Héctor Barajas-Martinez; Elijah R Behr; Connie R Bezzina; Jeroen Breckpot; Philippe Charron; Priya Chockalingam; Lia Crotti; Michael H Gollob; Steven Lubitz; Naomasa Makita; Seiko Ohno; Martín Ortiz-Genga; Luciana Sacilotto; Eric Schulze-Bahr; Wataru Shimizu; Nona Sotoodehnia; Rafik Tadros; James S Ware; David S Winlaw; Elizabeth S Kaufman; Takeshi Aiba; Andreas Bollmann; Jong Il Choi; Aarti Dalal; Francisco Darrieux; John Giudicessi; Mariana Guerchicoff; Kui Hong; Andrew D Krahn; Ciorsti MacIntyre; Judith A Mackall; Lluís Mont; Carlo Napolitano; Juan Pablo Ochoa; Petr Peichl; Alexandre C Pereira; Peter J Schwartz; Jon Skinner; Christoph Stellbrink; Jacob Tfelt-Hansen; Thomas Deneke Journal: Europace Date: 2022-09-01 Impact factor: 5.486