HEREDITARY INCREASE OF PLASMA HISTIDINE-RICH GLYCOPROTEIN ASSOCIATED WITH ABNORMAL HEPARIN-BINDING (HRG EINDHOVEN)

Plasma histidine-rich glycoprotein (HRG) was found to be persistently increased in a patient with a history of recurrent arterial thromboemb olic events. The mean concentration was 270% of normal pooled plasma. Increased HRG was found in eight of the 17 relatives studied, but none of them has experienced thrombo-embolism yet. Apparently, increased H RG was hereditary with autosomal dominant inheritance. A significant c orrelation was found between the increased plasma concentration of the protein and the age of the subjects (P <0.02), whereas no such relati on is present in a normal population. The plasma HRG of the proposita and 9 of her family members displayed abnormal binding to heparin, as assessed in a crossed affinity immuno-electrophoresis system: the usua l increase in mobility after binding to heparin was absent. The bindin g of this variant HRG to plasminogen was normal. This case represents the first abnormal HRG variant reported and it is proposed to designat e it: HRG Eindhoven.