Prenatal Diagnosis of Classical Phenylketonuria with Polymerase Chain Reaction, Automatic Sequencing, and Linkage Analysis with Short Tandem Repeats

Abstract

Objective: To share our experience of prenatal classical phenylketonuria (PKU) diagnosis using the polymerase chain reaction (PCR), automatic sequencing, and linkage analysis with short tandem repeats (STRs). Materials and Methods: Eight pregnant women who had delivered one baby with confirmed classical PKU were enrolled. They underwent amniocentesis and blood sampling. Genomic DNA was extracted from peripheral blood leukocytes and amniotic cells. Oligonucleotide primers for each specific exon, intron, enhancer, and STR of intron 3 were used for PCR amplification. The sequence was analyzed and the mutant pattern was determined. Results: Of the eight fetuses, one was normal, one had disease, five were disease-free carriers, and one test was indeterminate. Identified mutations included R408Q (n = 4), R241C (n = 3), R413P (n = 1), A434D (n = 1), and G257V (n = 1). Conclusion: The combination of amniocentesis and PCR can successfully detect fetuses with classical PKU early in pregnancy. Based on our experience, common mutations were R408Q and R241C.

Keywords

• hyperphenylalaninemia
• phenylalanine hydroxylase
• phenylketonuria
• polymerase chain reaction
• prenatal diagnosis
• short tandem repeat