A 2017 self-reported GWAS of mosquito bite size and itchiness found 15 immune-related loci — the first genetic look at why some people react to mosquito bites more than others.
Anyone who has compared bites with a companion after a walk outdoors knows that people react very differently to mosquito bites — some swell up and itch intensely, others barely notice. That variation is only partly about how often someone gets bitten; the immune reaction to a bite itself differs from person to person.
Jones et al. 2017, a collaboration between Pfizer and 23andMe, ran the first genome-wide association studies of self-reported mosquito bite reaction size (84,724 people), itchiness caused by bites (69,057 people), and perceived attractiveness to mosquitoes (16,576 people). Across all three, the study found 15 independent genome-wide-significant associations. The associated loci were enriched for immunity-related genes spanning multiple cytokine-signalling pathways, with suggestive enrichment in enhancer regions active in stimulated T-cells and in loci previously linked to central-memory T-cell levels — pointing to the adaptive immune system's role in how strongly a bite reaction develops.
A separate statistical analysis in the same paper (Egger regression) suggested that how itchy and how attractive to mosquitoes people perceive themselves to be are both driven, at least in part, by the same genetic factors that determine bite reaction size — evidence that these three self-reported traits share real underlying biology rather than being independent impressions.
This page's own variants include rs9276434 in HLA-DQA2, part of the same immune gene family the paper's authors highlight, plus rs35488337 in ETS1, rs11751172 in RUNX2, and rs6673928 in MAPKAPK2 among the itch-intensity variants, and rs3024971 in STAT6 and rs736801 in IRF1 — both well-known cytokine-signalling genes — among the bite-size variants.
This page describes self-reported bite reactions from a research study, not a medical diagnosis. Severe or spreading reactions to insect bites, or signs of infection, warrant medical evaluation regardless of anything on this page.
The traits studied here — bite size, itchiness, and perceived attractiveness — were all self-reported by participants rather than measured in a clinical setting. This page does not address mosquito-borne disease risk, which depends on exposure and pathogen biology rather than bite reaction intensity.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Mosquito Bite Reaction comes down to these specific, well-studied positions — not a diagnosis. 30 positions are linked to this page; the ones this page's own text discusses are shown first.
NCF4 · rs5756391
See detailed info →DYRK2 · rs10878725
See detailed info →ADAMTS10 · rs4499342
See detailed info →RAPGEF6 · rs31251
See detailed info →MEIKIN · rs35149731
See detailed info →near HINT1 · rs4706006
See detailed info →The studies behind these variants recruited participants from different ancestries — a result found in one population doesn't always transfer to another. Based on 30 of 30 linked studies with a resolved discovery ancestry.
Databases, guidelines and references
Part of the difference is genetic. A 2017 study found 15 loci associated with self-reported bite reaction size and itchiness, many of them in immune-related genes involved in cytokine signalling.
Studying self-reported bite reaction size (84,724 people), itchiness (69,057 people), and perceived attractiveness to mosquitoes (16,576 people), it found 15 independent genome-wide-significant loci, enriched for immune and cytokine-signalling genes.
The paper's own statistical analysis suggested they share underlying genetic factors with bite reaction size, rather than being independent traits.
No. This page covers self-reported bite reaction intensity, which is a different question from mosquito-borne disease risk — that depends on exposure and pathogen biology.
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.