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Alkaptonuria

Synonyms
Alcaptonuria; Alkaptonuric ochronosis; Homogentisic acid oxidase deficiency; Homogentisic acidura; Ochronosis, hereditary
Modes of inheritance
Autosomal recessive inheritance (Orphanet)

Summary

Excerpted from the GeneReview: Alkaptonuria
Alkaptonuria is caused by deficiency of homogentisate 1,2-dioxygenase, an enzyme that converts homogentisic acid (HGA) to maleylacetoacetic acid in the tyrosine degradation pathway. The three major features of alkaptonuria are dark urine or urine that turns dark on standing, ochronosis (bluish-black pigmentation in connective tissue), and arthritis of the spine and larger joints. Ochronosis generally occurs after age 30 years; arthritis often begins in the third decade. Other manifestations can include pigment in the sclera, ear cartilage, and skin of the hands; aortic or mitral valve calcification or regurgitation and occasionally aortic dilatation; renal stones; prostate stones; and hypothyroidism.
Full text of GeneReview (by section):
Summary
Diagnosis
Clinical Characteristics
Genetically Related (Allelic) Disorders
Differential Diagnosis
Management
Genetic Counseling
Resources
Molecular Genetics
Chapter Notes
References
Authors:
Wendy J Introne
Monique Perry
Marcus Chen
view full author information

Available tests

28 tests are in the database for this condition.

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Clinical tests (28 available)

Biochemical Genetics Tests

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: AKU, HGO, HGD
    Summary: homogentisate 1,2-dioxygenase

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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