The disease phenylketonuria is an autosomal recessively inhe

The disease phenylketonuria is an autosomal recessively inherited disease. Mutations are found in the enzyme phenylalanine hydroxylase. Which is most likely true of these mutations? They have low penetrance. They are loss-of-function mutations. They are gain-of-function mutations. They arise from a trinucleotide repeat expansion.

Solution

And: phenylketonuria urea is an example of loss of function mutation due to the mutation in phenylalanine hydroxylase there by phenylalanine accumulated in the body.