Reclassification of genetic variants in children with long QT syndrome

Molecular Genetics & Genomic Medicine

Alexander Moscu‐Gregor¹  Cordula M. Wolf²  Gabriele Hessling²  Tobias Burkard²  Roman Gebauer³  Dominik S. Westphal⁴ 

[1] Center for Human Genetics and Laboratory Diagnostics Martinsried Germany;Department of Congenital Heart Disease and Pediatric Cardiology German Heart Center Munich, Technical University of Munich Munich Germany;Department of Pediatric Cardiology Heart Center Leipzig, University of Leipzig Leipzig Germany;Institute of Human Genetics Technical University of Munich Munich Germany;

关键词: ACMG;    cardiogenetics;    long QT syndrome;    Schwartz score;    variant classification;   

DOI  :  10.1002/mgg3.1300

来源: DOAJ

【 摘 要 】

Abstract Background Genes encoding cardiac ion channels or regulating proteins have been associated with the inherited form of long QT syndrome (LQTS). Complex pathophysiology and missing functional studies, however, often bedevil variant interpretation and classification. We aimed to evaluate the rate of change in variant classification based on current interpretation standards and dependent on clinical findings. Methods Medical charts of children with a molecular genetic diagnosis of LQTS presenting at our centers were retrospectively reviewed. Reinterpretation of originally reported variants in genes associated with LQTS was performed based on current knowledge (March 2019) and according to the “Standards and Guidelines for the Interpretation of Sequence Variants” by the ACMG 2015. Results About 84 distinct (likely) pathogenic variants identified in 127 patients were reinterpreted. In 12 variants (12/84, 14.3%), classification changed from (likely) pathogenic to variant of unknown significance (VUS). One of these variants was a hypomorphic allele escaping the standard variant classification. Individuals with variants that downgraded to VUS after reevaluation showed significantly lower Schwartz scores and QTc intervals compared to individuals with unchanged variant characterization. Conclusion This finding confirms genetic variant interpretation as a dynamic process and underlines the importance of ongoing genetic counseling, especially in LQTS patients with minor clinical criteria.

【 授权许可】

Unknown