← Glossary
Gene

DIO1

DIO1 encodes type 1 iodothyronine deiodinase, a selenocysteine-containing enzyme expressed mainly in liver, kidney, and thyroid that removes an iodine atom from thyroxine (T4) to produce the active hormone triiodothyronine (T3), and also clears reverse T3. Common DIO1 variants such as rs2235544 shift the balance of circulating T4 relative to T3, so they are used as markers of a person's inherited tendency toward more or less efficient peripheral T4-to-T3 conversion.

Traits DIO1 shapes

Markers (rsIDs)

Reference databases

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This page is for educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Genetic results describe tendencies and predispositions, not diagnoses. Always consult a licensed clinician before making decisions about your health, medications, or supplements.