Diagnosis of milder forms of phenylketonuria in the population of the Sverdlovsk region

Abstract

The paper presents the results of an extended genetic study of 39 children observed in the MC “Health Care of Mother and Child” (Ekaterinburg) with a «hyperphenylalaninemia». An analysis of the previously known results of the study in these patients (the p. R408W variant in the heterozygous in 13 probands) showed that the search for recurrent gene variants using the panel does not give the expected proving of the diagnosis and requires additional testing. Applying the «gold standard» of diagnosis - direct sequencing of the PAH gene, the diagnosis of phenylketonuria (PKU) was confirmed in 35 probands (89.8%) - 2 altered alleles were found in them, one pathogenic variant was found in 4 others. A study of the DNA of parents and siblings indicated a families’ variants of inheritance for all identified mutations. As a result of the study, the pathology spectrum of the PAH gene, currently in use for the population of the Sverdlovsk region, has undergone significant changes, which require a new approach to the genetic diagnosis of this hereditary pathology in the region.