A patient reports a change in colour of urine on air exposure. All are true about the condition shown below except:

Ans. C. Urine Benedict's test is negativea. Alkaptonuria leads to blackening of urine which is accelerated by exposure to sunlight and oxygen.b. The alkapton bodies are polymers of Homogentisic acid and are deposited in vertebral discs, cartilage of nose, pinna.c. Benedict's test is positive with muddy yellow precipitated. Nitisinone, is an inhibitor of the enzyme 4 hydroxyphenylpyruvate dioxygenase that produces Homogentisic acid.