Lack of Homogentisate oxidase enzyme causes
(B) Alkaptonuria # ALKAPTONURIA: The defective enzyme in alkaptonuria is homogentisate oxidase in tyrosine metabolism. Homogentisate accumulates in tissues & blood, gets oxidized to the corresponding quinones, which polymerize to give black or brown colour. For this reason, the urine of alkaptonuric patients resembles coke in colour.
Phenylketonuria
Alkaptonuria
Maple syrup urine disease
Homocystinuria
Miscellaneous (Bio-Chemistry)