Homogentisate Oxidase Deficiency

Homogentisic acid oxidase deficiency, known as alkaptonuria, is a rare inherited metabolic disorder in which the body does not fully break down a compound derived from certain amino acids, which builds up and deposits in tissues.

Characteristic signs: one of the typical features is that urine darkens when left exposed to air; over the years, color changes in cartilage and joint discomfort may appear.

Common causes: it is caused by a genetic alteration that affects a metabolic enzyme and is usually passed from parents to children.

Which specialist treats it? The pediatrician usually identifies the first signs and guides the workup together with specialists in metabolic diseases. If you notice striking darkening of the urine or early joint discomfort, it is worth seeing a doctor to clarify the cause.