Genetic and Phenotypic Variability between Families with Hereditary Protein S Deficiency

Summary While many mutations thought to result in protein S (PS) deficiency are known, there have been few attempts to relate genotype expression with plasma phenotype. We have investigated the nature and consequence of PS gene (PROS1) mutations in 17 PS-deficient families who presented with mixed type I and type III phenotypes. Seven different mutations were found in nine families: delG-34 (STOP codon at –24), Val-24Glu, Arg49Cys, Asn217Ser, Gly295Val, +5 G to A intron j and His623Pro. PS wild type (PSWT) and the five missense mutants were transiently expressed in COS-1 cells. All mutants expressed lower (p