True statement regarding a 3-week old child with Phenylketonuria is all, except –
Phenylamine should be restricted in diet, however, it should not be completely eliminated, as it is necessary for normal growth.
Phenylketonuria 

It is an autosomal recessive condition.
There is a deficiency of enzyme phenylalanine hydroxylase.

Pathophysiology

Because phenylalanine is not metabolised by hydroxylase, metabolism is shifted to the alternative pathway (see above explanation) and there is an increased concentration of -


Phenylalanine      
Phenylpuruvic acid 
Phenylacetic acid 
Phenylacetic acid 


Because phenylalanine is not converted into tyrosine, tyrosine becomes an essential amino acid.

Treatment :

The goal of therapy is to reduce phenylalanine and its metabolites in body fluids in order to minimize or prevent brain damage.
Administration of low phenylalanine levels is the mainstay of treatment.
Dietary treatment should be started as soon as after birth as the diagnosis is established.
Because phenylalanine is not synthesized in the body, Tyrosine becomes an essential A.A. in this disorder, and its adequate intake must be ensured.
Provocative protein meal tests helps in the diagnosis
Tyrosine becomes an Essential amino–acid in diet
Serum Phenylalanine is increased and urinary Phenyl Pyruvate level is elevated
Phenylalanine should be completely stopped in diet