| | Definition: | | This illness, caused by a recessive gene that causes a deficiency of the enzyme homogensitic acid deoxygenase, was the first recognized genetic disease. It is characterized by abnormal deposits in the connective tissue and urine which turn dark when exposed to air. Severe arthritis and blockages in arteries and heart valves can occur in later stages of the disease. Its incidence is about one in a million. |
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