Rapid detection of phenylketonuria mutations by non-radioactive single-strand conformation polymorphism analysis

A non-radioactive single-strand conformation polymorphism (SSCP) method was used to detect various phenylketonuria (PKU) mutations in Japanese and Chinese patients. Arginine⁴¹³-to-proline (R413P) mutation in exon 12 of the phenylalanine hydroxylase gene was identified in a Japanese patient by this method. The segregation of the R413P mutation in the proband's family was clearly demonstrated and the carrier status of each family member was determined. Analysis of DNA fragments containing exon 7 originated from Chinese patients revealed two mutations, arginine²⁴³-to-glutamine (R243Q) and arginine²⁶¹-to-glutamine (R261Q), and a polymorphism, valine²⁴⁵-to-valine (V245V). Although R261Q has been identified previously among Caucasian subjects, this report is the first to describe this mutation among Orientals. Since the non-radioactive SSCP method employs pre-cast acrylamide gels and pre-made gel buffer strips combined with semi-automated temperature-controlled electrophoresis, it can be performed without much expertise in molecular biological techniques. The ability of this method to detect various mutations as demonstrated in this study and its ease of use make it feasible to detect PKU mutations in a routine DNA diagnostic laboratory.