Alkaptonuric

Part of speech: adjective, noun

Definitions

1. Relating to alkaptonuria, an inherited condition in which the body cannot break down homogentisic acid, causing dark urine
2. Describing a person or condition affected by alkaptonuria, a rare genetic disorder of amino acid metabolism
3. Characterizing the rare inherited disease alkaptonuria, marked by darkened urine and joint problems over time

Etymology: Alkaptonuria is a rare inherited disorder in which the body cannot fully break down the amino acids phenylalanine and tyrosine, so a substance called homogentisic acid builds up and is excreted in urine. Its name was coined in the late 1800s, and the story behind it lies in the chemistry rather than in any old word. The first part, "alkapton," was given by the German chemist Wilhelm Baeyer in 1862 for the dark pigment that appeared when urine from affected patients was left standing and made alkaline. Baeyer's coinage combines "alkali" with the Greek "ptōn," meaning fallen or fallen-down, which is a reference to the substance precipitating out of the urine. The name then passed into medical use for the condition itself. The second element, "-uric," comes from the Greek "ouron," meaning urine, which appears in many medical terms such as "uric acid." Attaching "-uric" to "alkapton" produced the noun "alkaptonuria" for the disorder, and the adjective "alkaptonuric" describes anything connected with it, such as a patient, a symptom, or a case.