Homogentistic acid deficiency

Ochronosis is named for the reddish-brown hue of tissue termed "ochre-like" that was first described by a young physician named Archibald Garrod in the early-19th century. In what he called an "inborn error of metabolism," Archibald Garrod changed history when he coined that term for the obscure "black urine" disease, alkaptonuria.

He proposed that ochronosis was due to deposition of a phenolic compound – "alkaptons" polymerizing into connective tissue - because the enzyme that could cleave it was absent and was inherited as a "chemical individuality."

This was insightful work given that this preceded the conceptualization of genes.

Reference

1. Phornphutkul C et al. Natural history of alkaptonuria. N Engl J Med. 2002 Dec 26;347(26):2111-21.