[A simple and reliable method for detection of the R408W mutation in exon 12 of the phenylalanine hydroxylase gene in the molecular diagnosis of phenylketonuria].

A new method for identification of R408W mutation common in phenylketonuria (PKU) patients in Russia and Eastern Europe is presented. The method is based on restriction of amplified exon 12. Amplification was achieved by PCR and was followed by restriction with StyI endonuclease. This enzyme specifically recognized allele R408W (C-T change in the position 1444 of the PAH gene) but not the normal allele. The method is easily reproduced both in DNA samples and in blood spots on the blotting paper (Gathrie cards) as well as in native cells from chorionic villi samples and amniocytes without preliminary DNA extraction. The method is very reliable and quick and has obvious advantages over other methods (ASO, ARMS) routinely used for identification of R408W mutation in the PKU high risk families.