Summary
We report a C/T dimorphism in the thrombomodulin (TM) gene that predicts an Ala455 → Val replacement in the sixth EGF-like domain of TM. This dimorphism has allelic
frequencies of 82 (Ala) and 18% (Val) in a normal population. In a group of protein
C deficient patients and in a group of subjects with unexplained thrombophilia the
allelic frequencies were found to be the same as in the normal population. This indicates
that with respect to thrombophilia the dimorphism is essentially neutral.