The STR252-IVS10nt546-VNTR7 phenylalanine hydroxylase minihaplotype in five Mediterranean samples.

IVS10nt546 (IVS10nt-11g→a) is the most common molecular defect of the phenylalanine hydroxylase gene causing phenylketonuria in Mediterranean populations. Previous studies have proposed various and alternative hypotheses concerning the geographical origin and pattern of diffusion of this mutation in this area. In this study, this issue was re-examined on a large sample (149) of “Mediterranean” IVS10nt546 mutant alleles analysed with multiallelic intragenic polymorphisms. The analysis of intragenic microsatellite (STR) and minisatellite (VNTR) polymorphisms shows allelic heterogeneity of the IVS10nt546 mutation. Eight STR and three VNTR alleles were found in association with the splicing def…