Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Lyonization
Medically reviewed by Min Clinic Staff | Updated: January 2026
Lyonization: The inactivation of an X chromosome. One of the two X chromosomes in every cell in a female is randomly inactivated early in embryonic development. Named after geneticist Mary Lyon.