Testosterone treatment and association with thrombin generation and coagulation inhibition in Klinefelter syndrome: A cross-sectional study.

•Men with Klinefelter syndrome do not demonstrate a severe pro-coagulant state.•Thrombin generation was lowest in testosterone treated patients.•Increased androgen action was associated with a milder coagulation profile.•Coagulation inhibitor levels were increased in Klinefelter syndrome.