To Modify or Not to Modify: Allele-Specific Effects of 3'UTR- KCNQ1 Single Nucleotide Polymorphisms on Clinical Phenotype in a Long QT 1 Founder Population Segregating a Dominant-Negative Mutation

J Am Heart Assoc. 2022 Sep 20;11(18):e025981. doi: 10.1161/JAHA.122.025981. Epub 2022 Sep 14.

Abstract

Background There are conflicting reports with regard to the allele-specific gene suppression effects of single nucleotide polymorphisms (SNPs) in the 3'untranslated region (3'UTR) of the KCNQ1 gene in long QT syndrome type 1 (LQT1) populations. Here we assess the allele-specific effects of 3 previously published 3'UTR-KCNQ1's SNPs in a LQT1 founder population segregating a dominant-negative mutation. Methods and Results Bidirectional sequencing of the KCNQ1's 3'UTR was performed in the p.Y111C founder population (n=232, 147 genotype positive), with a minor allele frequency of 0.1 for SNP1 (rs2519184) and 0.6 for linked SNP2 (rs8234) and SNP3 (rs107980). Allelic phase was assessed in trios aided by haplotype data, revealing a high prevalence of derived SNP2/3 in cis with p.Y111C (89%). Allele-specific association analyses, corrected using a relatedness matrix, were performed between 3'UTR-KCNQ1 SNP genotypes and clinical phenotypes. SNP1 in trans was associated with a significantly higher proportion of symptomatic phenotype compared with no derived SNP1 allele in trans (58% versus 32%, corrected P=0.027). SNP2/3 in cis was associated with a significantly lower proportion of symptomatic phenotype compared with no derived SNP2/3 allele in cis (32% versus 69%, corrected P=0.010). Conclusions Allele-specific modifying effects on symptomatic phenotype of 3'UTR-KCNQ1 SNPs rs2519184, rs8234, and rs107980 were seen in a LQT1 founder population segregating a dominant-negative mutation. The high prevalence of suppressive 3'UTR-KCNQ1 SNPs segregating with the founder mutation could contribute to the previously documented low incidence of cardiac events in heterozygous carriers of the p.Y111C KCNQ1 mutation.

Keywords: arrhythmia and electrophysiology; molecular cardiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Alleles
  • Humans
  • KCNQ1 Potassium Channel* / genetics
  • Mutation
  • Phenotype
  • Polymorphism, Single Nucleotide*
  • Romano-Ward Syndrome* / diagnosis
  • Romano-Ward Syndrome* / epidemiology
  • Romano-Ward Syndrome* / genetics

Substances

  • 3' Untranslated Regions
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human