We studied African-American Factor (FVII)-deficient variants and carri
ers in Georgia by measuring their levels of FVII antigen (FVIIAG) and
FVII procoagulant (FVIIC). Factor VIIAG was determined using enzyme-li
nked immunoassay (ELISA), whereas FVIIC was measured in two ways: 1) b
y fibrin clotting methods that employed human recombinant (HRFVIIC), h
uman placental(HPFVIIC), rabbit brain (RBFVIIC), and bovine brain (BBF
VIIC) thromboplastins; and 2) by an amidolytic method (AMFVIIC). Proth
rombin time tests (PT) were also performed by standard methods. These
4 FVII-deficient patients and 3 carriers demonstrated the following re
sults: PT: 18.2 +/- 6.5 sec; FVIIAG: 73.0 +/- 14.9%; HRFVIIC: 30.6 +/-
20.3%; HPFVIIC: 30.5 +/- 21.4%; RBFVIIC: 25.3 +/- 21.4%; BBFVIIC: 30.
6 +/- 17.5%; AMFVIIC: 44.1 +/- 18.3%. We conclude that a group of clin
ically mild African-American FVII-deficient variants exists in Georgia
. This group is characterized by the presence of FVIIAG and decreased
FVIIC, using a variety of thromboplastins; an excellent correlation wa
s noted for both human thromboplastins. (C) 1994 Wiley-Liss, Inc.