Factor XIII levels in five families of patients with inherited factor XIII deficiency: support for an autosomal recessive inheritance.

Using quantitative methods, f.XIII activity and levels of subunits a and b have been measured in 5 families of 6 patients with inherited XIII deficiency, including 2 children of a XIII deficient male. The parents, as a group, and the children, individually, have low XIII activity and low levels of subunit A when compared to controls. These findings provide further support for an autosomal inheritance of f.XIII deficiency. The measurements, however, did not allow confident selection of individual heterozygotes as has been previously suggested and an explanation of this finding is offered.