Charter Molecular Genetics Laboratory, Chelsea, London, UK.
A heterozygous CGG-->TGG (Arg 15-->Trp) substitution was detected in a family with inherited type II protein C deficiency and recurrent venous thrombosis. The mutation, which co-segregates with the deficiency state, occurs in a conserved pentapeptide within the gamma-carboxyglutamic acid (Gla) domain of the protein.