3 NOVEL MISSENSE MUTATIONS IN UNRELATED JAPANESE PATIENTS WITH TYPE-IAND TYPE-II PROTEIN-S DEFICIENCY AND VENOUS THROMBOSIS

A molecular analysis of protein S deficiency in three unrelated Japane se patients was performed. An approximately 50% reduction in both func tional and immunologic levels of protein S was detected in the plasmas from two unrelated patients, designated protein S Osaka 3. and protei n S Osaka 2, An approximately 50% reduction in the functional level, b ut a normal immunologic level of protein S, was detected in plasma fro m a third patient, designated protein S Osaka 3. All of the exons and exon/intron junctions of the protein S gene were studied using a strat egy combining polymerase chain reaction amplification and rapid nonrad ioactive single-strand conformational polymorphism analysis. We identi fied a G-to-A change in exon X of the protein S gene in protein S Osak a 1. This mutation resulted in the substitution of Gly for Ser at posi tion 295 in the sex hormone-binding globulin-like region. In protein S Osaka 2, a G-to-C change at the position of the 3' end of exon III wa s identified, leading to the amino acid substitution of Val46 by Leu i n the aromatic stack region. In protein S Osaka 3, an A-to-G change in exon II was identified, leading to the substitution of Lys9 by Glu in the Gla domain. It was concluded that the Gly295-to-Ser mutation and Val46-to-Leu mutation cause type I protein S deficiency and that the L ys9-to-Glu mutation causes type II deficiency. (C) 1998 Elsevier Scien ce Ltd.