Overall, 38% of the patients had a positive response, mostly MHP and mild PKU patients, all with at least one missense mutation with presumed residual activity.
The IQ of PAH-deficient mothers with a severe PKU mutation in combination with a MHP mutation or a mild PKU mutation was 99 and 96, respectively, whereas the IQ of PKU mothers with two severe PKU mutations or with one severe and one moderate PKU mutation was 83 and 84, respectively.