STUDY OF A PROTEIN-S GENE POLYMORPHISM AT DNA AND MESSENGER-RNA LEVEL IN A FAMILY WITH SYMPTOMATIC PROTEIN-S DEFICIENCY

A protein S gene polymorphism, detectable by restriction analysis of amplified exonic sequences, was investigated in a family with members affected by protein Sdeficiency, deep vein thrombosis and ictus. The clinical laboratory findings as well as RFLP analysis were consistent with the presence of a type WP III protein S deficiency clearly marked by a polymorphic allele, thus enabling us todetermine the carrier status in several subjects. The RFLP analysis, extended to platelet mRNA after reverse transcription and amplification, demonstrated thatthe mRNA produced by the putative defective gene was present in a subject affected by thrombosis