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PKU question please help!?
Is the disorder PKU dominant or recessive? EXPLAIN at a biochemical level, including the symptoms that result. Also, how can a special diet from birth have a positive effect on the outcome?
1 Answer
- Anonymous1 decade agoFavorite Answer
First of all it is recessive.
Basically, PKU or Phenylketonuria is a disorder where a mutated gene causes the enzyme phenylalanine hydroxylase (PAH) to not form correctly. This enzyme is responsible for hydrolyzing phenylalanine (Phe) (which is an essential amino acid that is derived from eating foods with Phe in it) into Tyrosine (Tyr) another amino acid. Because this enzyme does not form correctly the body cannot properly metabolize Phe to Tyr but instead the buildup of Phe will convert to phenylpyruvate also known as phenylketone and can be detected in urine (hence phenylketoneuria).
By allowing for a low Phe diet many adverse side effects of PKU can be avoided such as mental retardation, brain damage, and seizures. These are all caused by the buildup of Phe and phenylpyruvate.