8 NEW MUTATIONS OF THE PHENYLALANINE-HYDROXYLASE GENE IN ITALIAN PATIENTS WITH HYPERPHENYLALANINEMIA

This report identifies eight new mutations of the phenylalanine hydrox ylase gene detected in Italian patients with hyperphenylalaninemia. Th e trivial name of the mutations, predicted phenotypic effect, and popu lation of origin (Italian region) are as follows: F55L (nonconservativ e change: classic, moderate, mild PKU?; Sicily), IVS2nt-13 (splicing d efect, classic PKU; Tuscany), I65N (nonconservative change classic, mo derate, mild PKU ?; Sicily), H201Y (non-PKU HPA; Sicily), L269L (non P KU HPA, or polymorphism; Sicily), IVS7nt3 (splicing defect or polymorp hism; Sicily), I283N (classic PKU; Sicily), IVS12nt2 (splicing defect, classic PKU; Sicily and Apulia). In Sicily, the relative frequency of mutations F55L, I65N, H201Y, I269L, IVS7nt3, I283N, IVS12nt2 is <1%. The seven new mutations identified in the Sicilian population increase the remarkable genetic heterogeneity typical of this population with an estimated homozygosity value at the PAH locus of 0.041. (C) 1998 Wi ley-Liss, Inc.