Phenylketonuria (PKU) is a common inborn error of amino acid metabolism in which the enzyme phenylalanine hydroxylase, which converts phenylalanine to tyrosine, is functionally impaired due to pathogenic variants in the PAH gene. Thirty-four Brazilian patients with a biochemical diagnosis of PKU, from 33 unrelated families, were analyzed through next-generation sequencing in the Ion Torrent PGM™ platform. Phenotype–genotype correlations were made based on the BioPKU database. Three patients required additional Sanger sequencing analyses. Twenty-six different pathogenic variants were identified. The most frequent variants were c.1315+1G>A (n = 8/66), c.473G>A (n = 6/66), and c.1162G>A (n = 6/66). One novel variant, c.524C>G (p.Pro175Arg), was found in one allele and was predicted as likely pathogenic by the American College of Medical Genetics and Genomics (ACMG) criteria. The molecular modeling of p.Pro175Arg indicated that this substitution can affect monomers binding in the PAH tetramer, which could lead to a change in the stability and activity of this enzyme. Next-generation sequencing was a fast and effective method for diagnosing PKU and is useful for patient phenotype prediction and genetic counseling.

Assessment of newborn screening in the public health system of a municipality in northern Rio Grande do Sul

Background/Objectives: Hepatic glycogen storage diseases (GSDs) are inherited metabolic disorders that affect glycogen synthesis or breakdown, primarily involving the liver and muscles. Treatment typically consists of strict dietary management, including the consumption of uncooked cornstarch. However, there is limited research on feeding challenges and the associated stress experienced by parents of children with GSDs. This study aims to assess feeding difficulties in children with GSDs and the level of parental stress. Methods: A total of 29 caregivers of children aged 6 months to <7 years participated. Feeding difficulties were evaluated using the Brazilian Infant Feeding Scale (Escala Brasileira de Alimentação Infantil—EBAI), while parental stress was measured using the Parental Stress Scale (Escala de Estresse Parental—EEPa). Data were collected in 2020, and the study was approved by the ethics committee. Results: The majority of the children were male (19/10), with a mean age of 47.75 months and an average age of diagnosis of 8.39 months. GSD type Ia (n = 15) and type Ib (n = 5) were the most prevalent, followed by types III and IX (n = 2). Among the participants, 22 out of 29 (76%) reported feeding difficulties, categorized as mild (n = 7, 24%), moderate (n = 7, 24%), and severe (n = 8, 28%). EBAI scores were higher in female patients and in those who did not eat meals with their family. Only one caregiver exhibited high levels of parental stress, as measured by the EEPA scale. No significant correlation was found between feeding difficulties and parental stress. Conclusions: The findings confirm a high prevalence of feeding issues in children with GSDs, which significantly affects caregivers’ quality of life. Although no significant link between feeding difficulties and parental stress was identified, further research is needed to improve GSD management and provide better support for caregivers.