INCREASED THROMBOSIS INCIDENCE IN A FAMILY WITH AN INHERITED PROTEIN-S DEFICIENCY AND A HIGH OXYGEN-AFFINITY HEMOGLOBIN-VARIANT

Inherited protein S deficiency and the presence of a rare high oxygen affinity hemoglobin variant: Hb Rainier [beta 145 (HC2) Tyr --> Cys] were found in a family. Among 16 studied members, nine were found as carriers of protein S deficiency (type I with decrease of total, free, and activity levels). Six subjects carried the high-affinity hemoglobin variant, which displayed an increase of blood viscosity. Four members combined both abnormalities. Three had thrombotic accidents before the age of 30. We suggest the combination of protein S deficiency and the presence of this hemoglobin variant can lead to a severe primary hypercoagulable state with pathological consequences compared to each genetic defect alone. (C) 1994 Wiley-Liss, Inc.