Mutational and phenotypic analysis of hyperphenylalaninaemia in Southern Ireland

Abstract

Phenylketonuria (PKU) is the most common inherited defect of amino acid metabolism in the Irish population occurring at a frequency of 1/4,500 live births. It is caused by a deficiency of the hepatic enzyme Phenylalanine Hydroxylase (PAH). To date, over 400 mutations have been identified at the PAH locus. These mutations cause varying degrees of reduction in enzyme activity and combine to produce a wide range of phenotypes. The primary aim of this study was to determine the spectrum of mutations responsible for PAH deficiency in the Irish population.