an analysis of the urinary porphyrin precursors ( delta-aminolaevulinic acid and porphobilinogen ) , the determination of toal porphyrin excretion and the separation of haem precursors in the urine according to the number of carboxylic groups demonstrate different degrees of biochemical severity in the individual consanuinious members of this patient 's family .
C2917401
porphyrin precursors
C0002563
delta-aminolaevulinic acid