Family pedigree. The propositus (arrow) with previously determined plasma fibrinogen levels assessed by thrombin-clottable protein shown below with immunodetectable fibrinogen (in parentheses). Inheritance of the fibrinogen G exon 9 T to C mutation resulting in a S378P amino acid substitution is shown in black. Gray-shaded objects represent the normal T allele and hatched bars represent the mutant C allele. The affected individual not genotyped is indicated by the shading.