Hereditary porphobilinogen synthase deficiency in human associated with acute hepatic porphyria

Summary Deficient porphobilinogen-synthase (PBG-S) of a previously reported patient with PBG-S defect porphyria (red cell PBG-S activity 2% of the physiological level) has been characterized in erythrocytes after DEAE cellulose chromatography, ultrafiltration and polyacrylamide gel electrophoresis: Residual specific activity of 2.5%, increase of K_m, but identical fractionation, concentration and electrophoretic mobility of the enzyme protein compared to controls. These results provide evidence for a structural mutation of the gene specifying the enzyme PBG-S connected with a homozygous state of this new enzymatic type of hereditary acute porphyria.