PUBLICATION

The utility of zebrafish cardiac arrhythmia model to predict the pathogenicity of KCNQ1 variants

Authors
Cui, S., Hayashi, K., Kobayashi, I., Hosomichi, K., Nomura, A., Teramoto, R., Usuda, K., Okada, H., Deng, Y., Kobayashi-Sun, J., Nishikawa, T., Furusho, H., Saito, T., Hirase, H., Ohta, K., Fujimoto, M., Horita, Y., Kusayama, T., Tsuda, T., Tada, H., Kato, T., Usui, S., Sakata, K., Fujino, N., Tajima, A., Yamagishi, M., Takamura, M.
ID
ZDB-PUB-230312-33
Date
2023
Source
Journal of Molecular and Cellular Cardiology   177: 50-61 (Journal)
Registered Authors
Kobayashi, Isao
Keywords
Action potential duration, CRISPR/Cas9, KCNQ1, Long QT syndrome, Variants of unknown significance, Zebrafish
MeSH Terms
  • Animals
  • Humans
  • KCNQ1 Potassium Channel/genetics
  • Long QT Syndrome*/genetics
  • Mink/genetics
  • Mutation
  • RNA, Complementary
  • Virulence
  • Zebrafish*/genetics
PubMed
36898499 Full text @ J. Mol. Cell. Cardiol.
Abstract
Genetic testing for inherited arrhythmias and discriminating pathogenic or benign variants from variants of unknown significance (VUS) is essential for gene-based medicine. KCNQ1 is a causative gene of type 1 long QT syndrome (LQTS), and approximately 30% of the variants found in type 1 LQTS are classified as VUS. We studied the role of zebrafish cardiac arrhythmia model in determining the clinical significance of KCNQ1 variants. We generated homozygous kcnq1 deletion zebrafish (kcnq1del/del) using the CRISPR/Cas9 and expressed human Kv7.1/MinK channels in kcnq1del/del embryos. We dissected the hearts from the thorax at 48-72 h post-fertilization and measured the transmembrane potential of the ventricle in the zebrafish heart. Action potential duration was calculated as the time interval between peak maximum upstroke velocity and 90% repolarization (APD90). The APD90 of kcnq1del/del embryos was 280 ± 47 ms, which was significantly shortened by injecting KCNQ1 wild-type (WT) cRNA and KCNE1 cRNA (168 ± 26 ms, P < 0.01 vs. kcnq1del/del). A study of two pathogenic variants (S277L and T587M) and one VUS (R451Q) associated with clinically definite LQTS showed that the APD90 of kcnq1del/del embryos with these mutant Kv7.1/MinK channels was significantly longer than that of Kv7.1 WT/MinK channels. Given the functional results of the zebrafish model, R451Q could be reevaluated physiologically from VUS to likely pathogenic. In conclusion, functional analysis using in vivo zebrafish cardiac arrhythmia model can be useful for determining the pathogenicity of loss-of-function variants in patients with LQTS.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping