NOD2 — Crohn's disease risk
One copy of the NOD2 R702W variant detected.
You have one copy of the NOD2 R702W gene change, which modestly raises Crohn's disease risk.
Modestly elevated lifetime risk of Crohn's disease. Most carriers never develop it; smoking is a much stronger lifestyle risk factor for ileal Crohn's.
Your lifetime Crohn's disease risk is modestly raised. Most people with this change never develop Crohn's, and smoking has a much larger effect than this gene change on the type of Crohn's that affects the small intestine.
What this means
NOD2 encodes an intracellular pattern-recognition receptor that senses bacterial peptidoglycan. R702W is one of three common Crohn's-associated variants (R702W, G908R, and L1007fs). Together they explain ~15–20% of Crohn's heritability. Risk is highest for those carrying two damaged copies in any combination (compound heterozygous or homozygous).
NOD2 acts like a smoke detector inside your immune cells — it spots pieces of bacteria and triggers a response. R702W is one of three common NOD2 changes that affect this sensing job (the others are G908R and L1007fs). Between them, they account for roughly 15–20% of the inherited risk of Crohn's disease. The biggest risk is for people who carry two damaged NOD2 copies in any combination — either two of the same change or one each of any two of the three.
Caveats
- Three NOD2 variants together carry the full Crohn's signal — this is one of them.
- Smoking substantially modifies Crohn's risk; not smoking helps regardless of NOD2 status.
- Incomplete penetrance — most carriers never develop Crohn's.