Genetic landscape of phenylketonuria in Brazil.

Phenylketonuria (PKU), one of the most common inherited metabolic disorders, is caused by biallelic loss-of-function variants in the phenylalanine hydroxylase (PAH) gene. More than 1000 pathogenic variants have been described in this gene. Although genotype-phenotype correlations are imperfect, PAH genotypes can influence treatment decision-making. To better characterize the genetic landscape of PKU in Brazil, we compiled a dataset of PAH genotypes from 742 patients by combining data from the literature (n = 486), public databases (n = 117), and direct physician reports (n = 139). Most patients were classified as having classical PKU (n = 455/742; 61.3%). The most prevalent variants were c.1162G > A (16.6%), c.1066-11G > A (13.9%), and c.782G > A (11.8%), which are also the predominant ones in Portugal, Spain, and Latin America. This study confirms the allelic heterogeneity of PKU in the Brazilian population and provide relevant insights to support public health policies for this disorder.