Amplification of phenylalanine hydroxylase and cystathionine β‐synthase transcripts in human peripheral lymphocytes by RT‐PCR

A simple, rapid, reliable and convenient method was developed to analyze the gene defects in Phenylketonuria (PKU) and Homocystinuria (HCU). In this method, illegitimately transcribed phenylalanine hydroxylase (PAH) and cystathionine β‐synthase (CBS) mRNAs in peripheral lymphocytes were used as templates for amplification by RT‐PCR. The amplified products were confirmed by restriction enzyme digestions, southern blot hybridizations and sequencing. Point mutations in the protein coding region and splice junction mutations of PAH and CBS can be analyzed by this method.