Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — your resource for evidence-based guidance on genetics & health. Browse all Genetics & Health education

Everyone catches colds, but not everyone catches them the same way. Some people shrug off a cold in two days; others are flattened for a week by the same virus. Part of that difference is exposure and general health — and part of it is genetic. Your immune system’s first responders are built from genes, and small differences in those genes can change how hard a common cold hits.

This article explains the named gene variants researchers link to cold susceptibility and severity, what the science actually supports, and how pathway-level genetic insight fits in. It is educational and does not diagnose, treat, or prevent any illness.

Why colds vary so much between people

The common cold is caused by many viruses, with rhinoviruses the most frequent. Severity depends on how quickly your innate immune system detects the virus, how strong the resulting inflammation is, and how well your airway cells resist infection in the first place. Each of those steps runs on proteins encoded by genes — which is where inherited differences enter the picture.

CDHR3: the rhinovirus doorway

One of the most specific genetic links to colds involves CDHR3. The variant rs6967330 changes a receptor on airway cells that rhinovirus-C uses to get inside. Carriers of the risk version display more of this receptor, and studies connect the variant to more frequent and more severe rhinovirus infections, particularly in children and in people with asthma. CDHR3 is a clear example of genetics shaping a very specific step of the cold process — the virus’s entry point.

Interferon and antiviral defense: IFITM3 and IFNL4

Once a virus is inside, your cells fire off interferons, the alarm signals of antiviral defense. IFITM3 makes a protein that physically restricts viruses from entering cells, and a variant (rs12252) has been studied in the context of more severe respiratory viral illness. Variants in the interferon-lambda region (IFNL4, rs368234815) influence how vigorously the airway mounts its early antiviral response. Together these genes help set how fast you contain a cold.

Inflammation and vitamin D pathways

Symptoms like congestion and fatigue are partly your own inflammatory response, not just the virus. Variants in inflammatory signaling genes and in the vitamin D receptor (VDR) have been studied in relation to respiratory infection frequency and severity, since vitamin D signaling helps regulate airway immunity. This is why two people with identical exposure can feel very different: their inflammatory tuning differs.

The same tuning that clears a virus quickly can also produce more noticeable symptoms, because congestion and aches are byproducts of an active immune response. A brisk response is not automatically bad, and a mild one is not automatically better. What matters is balance, and that balance reflects genetics, age, and overall health working together rather than any single switch.

What the research shows

The CDHR3 rs6967330 link to rhinovirus illness is among the most reproducible findings, while interferon-pathway variants show smaller, context-dependent effects. Across studies, no single gene determines cold severity — it is polygenic, layered on top of sleep, stress, age, and prior exposure. Genetics tilts the odds; it does not decide the outcome of any one cold.

Where pathway-level genetic insight fits

Genetic testing does not diagnose infections or predict whether you will get sick, and it is no substitute for medical care. What pathway-level insight offers is context about how your immune and inflammatory pathways are wired. The PlexusDx Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights, mapping the biological systems that shape those tendencies — educational context you can discuss with a qualified provider.

Frequently Asked Questions

Do genetics really affect how bad my colds are?

Yes, partly. Genes shape how quickly your immune system detects viruses and how strong your inflammatory response is. Variants in CDHR3 and interferon-pathway genes influence rhinovirus susceptibility and severity. Still, sleep, stress, age, and exposure matter enormously, so genetics tilts the odds rather than deciding any single cold.

Which genes are linked to cold severity?

CDHR3 (variant rs6967330) affects a receptor rhinovirus-C uses to enter airway cells, while IFITM3 and IFNL4 influence antiviral interferon defense. Vitamin D receptor (VDR) variants have also been studied in respiratory infection. No single gene controls cold severity — it reflects many small-effect variants working together.

Can a genetic test tell me if I will get a cold?

No. Genetic testing reports pathway-level tendencies, not predictions about specific infections. Whether you catch a cold depends mostly on exposure and overall health. Genetic insight can add educational context about your immune pathways, but it cannot forecast, diagnose, or prevent any illness on its own.

How can I support my immune resilience?

Evidence-based basics help most people: consistent sleep, regular activity, a nutrient-rich diet, stress management, and good hand hygiene. Discuss vitamin D or other supplements with a qualified provider rather than self-prescribing. Genetics may explain part of your tendency, but daily habits remain the most modifiable factor in immune resilience.

Curious about the pathways behind your own biology? The Precision Peptide Genetic Test reads pathway-level genetic signals and translates them into plain-language insight you can bring to a qualified provider. It maps your biology — it does not tell you what to put in your body.

The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways. It does not recommend, prescribe, or determine which peptides you should use. Consult a qualified healthcare provider before beginning any peptide protocol.

This article is part of the PlexusDx Education Hub. Browse all Genetics & Health education

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.