Hereditary prophobilinogen synthase deficiency in human associated with acute hepatic porphyria.

Deficient porphobilinogen-synthase (PBG-S) of a previously reported patient with PBG-S defect porphyria (red cell PBG-S activity approximately 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 Km, 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.