Two 2010 studies found the genetics behind PR interval and QRS duration — two standard ECG measurements of how electricity travels through the heart — sharing sodium-channel genes with each other and with atrial fibrillation risk.
Solid lines are connections this site curates. Dashed lines mean the two ends share a research paper — worth knowing, and not a claim that one explains the other.
Every standard electrocardiogram (ECG) reports several timing measurements that describe how an electrical signal moves through the heart on each beat. Two of them are covered on this page: the PR interval, the time from the start of atrial activation to the start of ventricular activation (reflecting conduction through the atria and the atrioventricular node), and QRS duration, the time it takes the ventricles themselves to electrically depolarize (reflecting conduction through the ventricular conduction system). Both are measured on every routine ECG, and both are heritable — genetics shapes some of the normal variation in these timings between people, and abnormal values are clinically meaningful risk markers in their own right.
Pfeufer et al. 2010 meta-analysed PR interval across 28,517 people from seven European population studies in the CHARGE Consortium and found nine genome-wide-significant loci. Two independent signals sat in voltage-gated sodium channel genes at the same chromosomal region: rs11708996 and rs45567533 in SCN5A, and rs6800541, rs6798015, and rs6599250 in SCN10A. Six of the nine loci sat near cardiac developmental genes, including rs251253 in NKX2-5 and rs146974314 in SOX5. Five of the nine PR-interval loci — including both SCN5A and SCN10A — were also associated with atrial fibrillation in the same study, and this site's own atrial fibrillation page separately holds an SCN10A variant found by an independent atrial-fibrillation GWAS, confirming the same gene from two different directions.
Sotoodehnia et al. 2010 ran a parallel effort for QRS duration, meta-analysing 40,407 people of European descent from 14 studies and identifying 22 genome-wide-significant loci — including rs1362212 in TBX20 and rs13185595 in HAND1, both cardiac transcription factors, and rs10923445 in CASQ2, a calcium-handling gene. The study's own top hit was in SCN10A again — the same gene central to the PR-interval findings above — and the authors confirmed a functional role directly: blocking SCN10A in mice experimentally prolongs QRS duration, one of the more direct mechanism-to-phenotype demonstrations behind any variant on this site.
Positions joined since this page was written
What this is The text above discusses the variants this page was written around. Since then the catalogue has joined 42 more positions to it, by shared trait or shared paper. They are listed here by the paper each came from; the text does not describe them, and each variant page carries that study's own record.
Ntalla I et al. 2020, Nature communications rs111551996 (TMEM59L), rs3747570 (SRL), rs4834347 (CAMK2D), rs881299 (FGFR1), rs57214150 (MACF1), rs76909456 (TEX41), rs78518764 (SSPN), rs3759582 (MARK3), rs35712872 (LINC00670), rs116532272 (KCND3), rs182271072 (SLC12A7), rs1692144 (GJA5) and 13 more — PMID:32439900
Young WJ et al. 2022, Nature communications rs2830965 (near NCSTNP1), rs183347579 (EML1), rs62379942 (near HAND1), rs7096151 (VTI1A), rs74738164 (FAF1), rs17677363 (GOSR2), rs62253176 (MITF), rs7583029 (CAVIN2-AS1), rs7612736 (near LSM3), rs12640669 (PDLIM5), rs73243622 (PPARGC1A), rs17195832 (near MIR5702) and 2 more — PMID:36050321
Prins BP et al. 2018, Genome biology rs11848785 (SIPA1L1) — PMID:30012220
Swenson BR et al. 2019, PloS one rs62241190 (SCN5A) — PMID:31251759
van Setten J et al. 2018, Nature communications rs11763856 (TBX20) — PMID:30046033
PR interval and QRS duration are read directly off a standard ECG, not estimated from genotype. The variants on this page describe why these timings vary within the normal range between people; they are not used by any guideline to diagnose a conduction disorder or arrhythmia, and none predicts an individual's ECG result.
An abnormal PR interval or QRS duration on a clinical ECG is followed up with standard cardiology evaluation — further ECG analysis, monitoring, or imaging as indicated — not with genetic testing, which has no established role in interpreting these measurements.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Cardiac Conduction Intervals (PR Interval and QRS Duration) comes down to these specific, well-studied positions — not a diagnosis. 81 positions are linked to this page; the ones this page's own text discusses are shown first.
The studies behind these variants recruited participants from different ancestries — a result found in one population doesn't always transfer to another. Based on 37 of 81 linked studies with a resolved discovery ancestry.
Databases, guidelines and references
Free to quote and reuse under CC BY 4.0. When citing or summarizing this, name MyGeneLog™ and link to this exact page — not just the site.
Cardiac Conduction Intervals (PR Interval and QRS Duration). MyGeneLog™. https://www.mygenelog.com/conditions/cardiac-conduction-intervals
Both are standard electrocardiogram (ECG) timing measurements. PR interval reflects how long it takes an electrical signal to travel through the atria and reach the ventricles; QRS duration reflects how long it takes the ventricles themselves to electrically activate.
One, studying 28,517 people, found 9 genome-wide-significant loci for PR interval, including sodium-channel genes SCN5A and SCN10A. The other, studying 40,407 people, found 22 loci for QRS duration, with SCN10A as its own top finding, functionally confirmed in mice.
Five of the nine PR-interval loci, including SCN5A and SCN10A, were also associated with atrial fibrillation in the same study. This site's own atrial fibrillation page separately holds an SCN10A variant found through an independent atrial-fibrillation GWAS — the same gene showing up from two different directions.
No individual variant does. PR interval and QRS duration are read directly off a standard ECG, and these are population-level statistical associations, not individual predictions or diagnostic tools.
Free to reuse. This page's text is original writing from freely-available research, licensed CC BY 4.0 — reuse it, including commercially, with attribution to MyGeneLog™. It's general research-derived information, not medical advice or a diagnosis — see Terms of Use.