Alkaptonuria

Part of speech: noun

Pronunciation: /ælˌkæptəˈnʊəɹɪə/

Definitions

1. A hereditary condition occurs due to an enzymatic defect that results in the body's inability to process a specific amino acid, causing joint pain and dark urine as byproducts of the metabolic dysfunction
2. This metabolic disorder is caused by a genetic mutation, leading to the excessive buildup of homogentisic acid and resulting in symptoms like arthritis and darkened bodily fluids
3. A genetic disorder characterized by an enzymatic failure to metabolize homogentisic acid, leading to joint issues and dark urine due to waste accumulation

Etymology: Alkaptonuria is a compound of two parts, and the first is the stranger one. "Alkapton" was coined in the 1860s by the German chemist Carl Boedeker, who named a dark substance he found in the urine of an alkaptonuric patient. The word is built from "alkali" and "kapto", but the name was a poor fit: the substance was not an alkali, and the element that makes it turn dark is homogentisic acid, which oxidizes on contact with air. "Alkapton" survived as a label for the condition even though the chemistry it describes is not what the name suggests. The second element, "-uria", comes from Greek "ouron", meaning urine, and is the standard suffix for conditions in which a substance appears in the urine. So the word literally means "urine that darkens", and it describes the most visible symptom: urine that turns black or dark brown when left standing or exposed to air.