Combined hemophilia and PTC deficiency.

S INCE C)T’I’ C)’ described the disease ins I 803, hemophilia Isas been recogmnized primarily as a climiical entity. A severe bleeding t-emsdemicy especially associated with joint and deep tissue hemorrhage, a failure or delay ins clot formatiomi, amid a family history of sex-linked immheritance characterized a distinct chimucal picture. Iammy imivestigators have studied this disease its aim effort to ascert-aims the nature of the obvious blood coagulatiomi defect. mi the course of these investigatiomis, almost every factor known to l)e important its coagulation has beemi presumed to be abnormal in hemophilia; however, histomy has proven most of these claims baseless. The origimsal observations by Addis2 thata small amoumst of normal plasma or a crude globulin fraction derived from it was capable of completely correcting the hemophilic coagulation defect in vitro was not fully appreciated until confirmed I) other workers3 . some twenty-five years later. Subsequently, it was demomistrated that some substance, other than fibrinogen, in Cohn Fraction I could he employed for this purpose. It was also established that hemophilic plasma did not const-aims this globulin in normal amoumits. As a result, it was commomily accepted that the etiology of hemophilia had been established amid that the disease was characterized simply by an inherent deficiency of so-cabled antihemophilic globulin. Imi 1947, however, Pavlovskytm reported that the blood or plasma from certain hemophiliacs was capable of correcting the coagulation defect in the blood of amiother patienthaving the same clinical disease. This finding strongly implied that. more thami a single coagulatioli defect was involved. Further, the studies by Hill amid co-workers6 on the imiheritance of apparent-by typical hemophilia gave results suggestive of multiple factors in the causation of this disease. Aggeler amid co-workers7 in 1952, demomist-rated very conclusively that the deficiemmcy of a secommd thromboplastic factor, plasma thromboplastin component (PTC) (‘Oltld resultin a hemorrhagic cotsdition clinically indist-imiguishable from hemophilia. Its the same year, Biggs amid co-workers,5 as well as Schulman and Smith,9 report-ed cases apparently sufferimig from a deficiemicy of this fact-or. Re((’mttl V, Rosenthal and his collaboratorst#{176} have cabled attemit-ion to a third factor w-hich they term plasma t-hromhoplast-in antecedemit (PTA). Deficiemicy of this thromboplast-ic fact-or led t-o a condit-iomi thatpresented some clinical features differing slightly from classical hemophilia in the cases described. A family with several members showimsg 1)0th climsical and laboratory findings itsdicative of PTA-deficiency has recemitly beets studied its our laboratory in comparison with the eases reported imi this paper.1t In comitrastwith t-he t-hromboplastic deficiency comsditions described above,