True regarding PKU is all except:-
Diagnosis of PKU was detected by screening the new-born babies for the increased plasma levels of phenylalanine (PKU, 20-65 mg/dl; normal 1-2mg/dl). This was carried out by Guthrie test, which is a bacterial (Bacillus subtilis) bioassay for phenylalanine. Phenylpyruvate in urine can be detected by ferric chloride test (a green colour is obtained). Method of Choice is Tandem Mass Spectrometry, also for all the Inborn metabolic Error disease
Due to deficiency of phenyl alanine hydroxylase
Neurological symptoms are due to excess phenyl alanine
Blood phenyl alanine level >20 mg/dl causes severe disease
Method of choice for screening is urinary phenyl alanine by Guthrie;s test
NEET 2018