Homozygous protein C deficiency manifested by massive venous thrombosis in the newborn.
We studied a family in which two infants had died with massive venous thrombosis shortly after birth. Protein C antigen was undetectable by immunologic assays of plasma available from one infant. (Protein C is a potent naturally occurring anticoagulant that inactivates activated coagulation factors V and VIII). The parents, who were first cousins, both had partial protein C deficiency. Reduced protein C levels were also observed in 12 of 25 additional family members. None of the partially deficient family members (age range 4 to 70 years) had thrombotic episodes. Our data support the view that hereditary protein C deficiency is an autosomal disorder in which the homozygous state may be manifested by the virtual absence of plasma protein C and by fatal thrombosis in the neonatal period.
D000328:Adult; D001777:Blood Coagulation; D003241:Consanguinity; D005260:Female; D006023:Glycoproteins / Q000032:analysis / Q000172:deficiency*; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010375:Pedigree; D011486:Protein C; D013924:Thrombophlebitis / Q000209:etiology* / Q000235:genetics
D006023:Glycoproteins; D011486:Protein C