Biochemical identification of homogentisic acid pigment in an ochronotic Egyptian mummy

Roentgenograms of an Egyptian mummy, dating from 1500 B.C., showed extensive calcification of the intervertebral discs and articular narrowing in both hip and knee joints. Biopsy cores from the right hip showed parallel black zones in the region of the articular surfaces, leading to a clinical diagnosis of ochrinosis. The black pigment was extracted, analyzed, and compared to an air-oxidized homogentisic acid polymer. The two substances apparently were identical. The chemical evidence thus confirms the clinical finding of ochronosis, an autosomal recessive disorder. This is, so far as known, the earliest verified case of this disorder.