GYPSY PHENYLKETONURIA - A POINT MUTATION OF THE PHENYLALANINE-HYDROXYLASE GENE IN GYPSY FAMILIES FROM SLOVAKIA

A direct mutational analysis of the phenylalanine hydroxylase gene (PA H) in Gypsy families with phenylketonuria (PKU) has not yet been prese nted. However, they obviously represent a group at high risk for this inherited disease. We analyzed the PAH loci of 65 Gypsies originating from Eastern Slovakia by a combination of PCR amplification, direct se quencing and ASO hybridization. These studies uncovered 10 ''classical PKU'' patients to be homozygous for a R252W (CGG-TGG) transition, and 29 heterozygous carriers of this mutation. Fifteen control Caucasoid PKU patients from the Czech and Slovak Republics were selected. In thi s group we detected R252W mutation in two subjects (6.67% of all mutan t alleles). Both were compound heterozygous for two different mutation s. Previous haplotype studies of Welsh Gypsies with PKU were uninforma tive in the determination of heterozygosity. ASO hybridization served us effectively for the consequent analyses in Gypsy PKU-related famili es and to identify the carriers among the unrelated subjects. (C) 1994 Wiley-Liss, Inc.