Question

A disease called phenylketonuria causes mental retardation, reduces skin pigmentation, and also affects the coloration of urine. What kind of effect is exhibited by the gene responsible for this disease?

Answer 1

The disease is inherited when both parents have, on chromosome 12 (region q22 - q24.1), a mutation in the PAH gene encoding the enzyme phenylalanine hydroxylase, where the molecular defect is a single base substitution of thymine for adenine , obtained as an unstable protein product, which is transmitted to the child. (Excuse me, I don't write in English so well, yet, I'm Learning.)