Detection of point mutations of the phenylalanine hydroxylase gene and prenatal diagnosis of phenylketonuria.

The known mutant alleles of the human phenylalanine hydroxylase (PAN) gene were analyzed in 25 phenylketonuria (PKU) families from North China by using polymerase chain reaction and allele-specific oligonucleotide dot blot hybridization techniques. The results showed that the six mutations analyzed accounted for 62% of all PKU genes. The three most frequent mutations were R243Q, R413P and Y204C. Seven prenatal gene diagnoses were carried out in 6 PKU families and were confirmed after birth or by examination of aborted materials.