alkaptonuria
A doctor explains the genetic condition alkaptonuria to a patient using a medical diagram.
Noun: A rare, inherited, recessive metabolic disorder. It is characterized by the body's inability to properly break down two amino acids (tyrosine and phenylalanine), leading to the accumulation of a substance called homogentisic acid (also known as alkapton). This results in ochronosis (a bluish-black discoloration of connective tissue) and the presence of homogentisic acid in the urine, which may darken upon exposure to air.
- The diagnosis of alkaptonuria is often made after observing dark-stained diapers in an infant or dark urine that turns black upon standing.
- A key symptom of alkaptonuria in adults is the progressive darkening and degeneration of cartilage, particularly in the spine and large joints.
- Although alkaptonuria is present from birth, the symptoms of joint pain and discoloration often do not become apparent until adulthood.
- "Alkaptonuric arthritis": Refers to the severe, early-onset osteoarthritis that is a hallmark complication of alkaptonuria.
- The patient's debilitating back pain was attributed to alkaptonuric arthritis.
- The term is used in medical genetics and biochemistry to describe a specific inborn error of metabolism.
- Ochronosis (n): The clinical condition of bluish-black pigmentation in connective tissues (e.g., cartilage, skin) caused by the deposition of homogentisic acid polymer, which is a consequence of alkaptonuria.
- Homogentisic acid (n): The specific chemical (alkapton) that accumulates in the body and is excreted in the urine of individuals with alkaptonuria.
- Homogentisic aciduria: A more biochemically precise synonym, directly naming the substance (homogentisic acid) found in the urine.
- AKU: A common medical abbreviation for alkaptonuria.
This word has a single, specific meaning in medical terminology. It does not have common idiomatic or figurative uses. It refers exclusively to the genetic disease.
A doctor explains the genetic condition alkaptonuria to a patient using a medical diagram.
- a rare recessive metabolic anomaly marked by ochronosis and the presence of alkapton in the urine