Heterozygosity and Homozygosity in von Willebrand's Disease.

Abstract

Two persons believed to be homozygous for v.W.d. and their heterozygous parents were transfused with hemophilia A plasma. The parents showed extensive “new synthesis” of AHF while the children showed only 1/8 as much “new synthesis” as an unrelated group of v.W.d. heterozygotes. This result is taken to mean that the v.W.d. locus is not occupied by a regulatory gene. The result is consistent, however, with the idea that both the autosomal and the X-locus which affect AHF biosynthesis are occupied by structural genes coding sub-units of the molecule. There is still no direct evidence that the latter hypothesis is correct, however.