Abstract
Phenylketonuria (PKU) occurs due to a mutation in the gene encoding phenylalanine hydroxylase, which results in inability to convert phenylalanine into tyrosine. DNA methylation is an important epigenetic modification of the genome. Many human diseases have been detected to be related to aberrant DNA methylation. Investigating the leukocytes of PKU patients exposed to phenylalanine has shown a wide range of methylation, which indicates DNA methylation changes as a biochemical marker. In this article, we reviewed evidence of DNA methylation in pathophysiology of PKU.