Which of the following gives a positive reaction with Ferrous chloride?
Phenylketonuria
Alkaptonuria
Maple syrup urine disease
Non
PhenylketonuriaDeficiency of phenylalanine hydroxylase is the cause for this disease. The genetic mutation may be such that either the enzyme is not synthesized, or a non-functional enzyme is synthesized.Laboratory Diagnosis A.Blood phenylalanine: Normal level is 1 mg/dl. In PKU, the level is >20 mg/dl. This may be demonstrated by chromatography. Tandem mass spectroscopy is the most reliable test, but is costly.B. Guthrie test is a rapid screening test.C.Ferric chloride test: Urine of the patient contains phenyl ketones about 500-3000 mg/day. This could be detected by adding a drop of ferric chloride to the urine. A transient blue-green color is a positive test. But this is a less reliable test.D.DNA probes are now available to diagnose the defects in phenylalanine hydroxylase and dihydrobiopterin deficiencyRef: Textbook of biochemistry (DM Vasudevan), 6th edition, page no: 207
Metabolism of protein and amino acid