Fibrinogen Baltimore III: congenital dysfibrinogenemia with a shortened gamma-subunit.

An abnormal fibrinogen has been found in an asymptomatic Negro female. Clinical laboratory findings were normal, except for a prolonged thrombin time which was corrected by addition of calcium. Fibrinopeptide release by thrombin and crosslinking by factor XIII also occurred normally, but fibrin monomer polymerization was delayed. Sodium dodecylsulfate-polyacrylamide gel electrophoresis disclosed that 50% of the gamma-subunits migrated with an apparent Mr of 45,500, approximately 1,500 Da smaller than normal. The evidence suggests that an internal sequence of 10-15 residues is missing from the gamma-subunit of the abnormal fibrinogen.