rs17221854
A SNP in the KCNQ1 gene on chromosome 11. Its most notable genotype is T;T: increased susceptibility to long QT syndrome
- Gene
- KCNQ1
- Location
- Chr 112,777,990 (GRCh38)
- Highest magnitude
- 4.0Very important
- Tested on
- 23andMe, AncestryDNA
Genotypes
As shown in 23andMe and AncestryDNA files.
- C;CGoodcommon in clinvar
- C;TBadincreased susceptibility to long QT syndrome
- T;TMost notableBadincreased susceptibility to long QT syndrome
On SNPedia: (C;C), (C;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other KCNQ1 SNPs
- rs17215500T;TLQT1 form of Long QT syndrome; Jervell and Lange-Nielsen syndromeVery important
- rs179489C;GRomano-Ward Long QT SyndromeVery important
- rs1800171A;GRomano-Ward Long QT SyndromeVery important
- rs12720459C;TLQT1 form of Long QT syndromeVery important
- rs104894252A;GRomano-Ward Long QT SyndromeVery important
- rs104894255A;GRomano-Ward Long QT SyndromeVery important
- rs120074177C;GRomano-Ward Long QT SyndromeVery important
- rs120074178A;GRomano-Ward Long QT SyndromeVery important
Notes
From SNPedia
Notes
rs17221854, also known as Arg583Cys or R583C, is a SNP in the KCNQ1 gene on chromosome 11. The rs17221854(T) allele has been reported as associated with long QT syndrome. Additionally, a person who developed QT prolongation and torsade de pointes while taking the drug dofetilide carried this (T) allele, leading the authors to hypothesize that this mutation was responsible for the patient's drug response. This variant meets the criteria published in 2013 by the ACMG regarding incidental findings in exome or genome sequencing, as a variant that they do recommend informing a patient about.
C;T
see discussion at rs17221854
T;T
see discussion at rs17221854
Source and license
Adapted from rs17221854 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.