Genetic Heterogeneity of Factor XIII Deficiency: First Description of Unstable A Subunits

Abstract

In previously reported cases, congenital deficiency of coagulation factor XIII resulted from the absence of the enzymatically active A subunits. In the faily reported here 2 members were heterozygous for an unstable A subunit which, in the homozygous state, or in the heterozygous state with the previously described null allele, would be expected to result in factor XIII deficiency. The implications that this new variant has on heterozygote screening are discussed.