Alkaptonuria (black urine disease, alcaptonuria or ochronosis) is a rare inherited genetic disorder of tyrosine metabolism. This is an autosomal recessive trait that is caused by a defect in the enzyme homogentisic acid oxidase (). The enzyme normally breaks down a toxic tyrosine byproduct, homogentisic acid (also called alkapton), which is harmful to bones and cartilage and is excreted in urine.
Chronic Illness
Nutrition and Metabolism Disorders

Alkaptonuria - A brief discussion about this disease and its statistics world wide. Followed by a case study of a 4 year old boy, whose parents noted the darkening of the urine to an almost black color when it was left standing.
Alkaptonuria and Ochronosis - A detailed look at these disorders, how it affects the many body parts, diagnosis, diet and treatment are discussed.
Meta Description: [ Alkaptonuria is a rare disease in which the body does not have enough of a specific enzyme. Ochronosis is a blue-black discoloration of bone, cartilage, and skin caused by deposits of ochre-colored pigment. ]
MedicineNet.com : Alkaptonuria - An article about this disease beginning with an explanation as to what it is, followed by how it is inherited, how it affects the joints, symptoms, diagnosis and treatment.
Meta Description: [ Explains arthritis conditions includes symptoms, causes, medications, and treatment. Written and reviewed by a Rheumatologist. ]
The Alkaptonuria Society - An information and support network for those people diagnosed with Alkaptonuria. Includes discussions, articles and related resources.
Meta Description: [ The Alkaptonuria Society is a charity that raises awareness and seeks a cure for a rare and serious genetic disease, Alkaptonuria. ]