alkaptenuria

In 1901 a London-based physician called Archibald Garrod
a number of patients whose urine turned black after exposure to the air
mostly young, patients did not seem to be in any pain or discomfort. the nappies of young infants and found large quantities of alkapton (now known as homogentisic acid) in their urine
Garrod noted that patients often had one or more siblings that were also affected and that their parents were often unaffected.
Garrod wanted to find out whether there was a genetic basis for the “peculiar mode of inheritance” of this “black-pee-disease”.
History / PE: Dark or black urine on standing Ochronosis (dark pigment in connective tissue) Arthritis
Diagnosis: Homogentisic acid in urine (confirmatory)
Differential Diagnosis:Phenylketonurea(musty odor urine, blue eyes, fair skin)
ALKAPTONURIA
•Autosomal recessive
–Homogentisicacid dioxygenase deficiency
•HGA accumulation causes ochronosis
–Blackening and destruction of cartilage and connective tissue
–Spine, hips, knees, shoulders, aortic valve