Genetic and clinical characterization of patients with phenylketonuria in Alagoas state, Brazil <br><b>[Abstract in English]</b>

Emerson de Santana Santos; Maria Alzira Almeida Rocha; Helen Mayara Nunes da Silva Oliveira; Doriane Costa; Tatiana Amorim; Angelina Xavier Acosta

Authors

Emerson de Santana Santos Universidade Federal de Alagoas - UFAL
Maria Alzira Almeida Rocha Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL
Helen Mayara Nunes da Silva Oliveira Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL
Doriane Costa Maternidade Escola Santa Mônica - MESM UNCISAL
Tatiana Amorim Escola Bahiana de Medicina e Saúde Pública
Angelina Xavier Acosta Faculdade de Medicina da Bahia - Universidade Federal da Bahia

Keywords:

PHENYLKETONURIA, PHENYLALANINE HYDROXYLASE, AMINO ACID METABOLISM, INBORN ERRORS, GENOTYPE, FENOTYPE, NEONATAL SCREENING, MUTATION, INTELLECTUAL DISABILITY, PROGNOSIS.

Abstract

AIMS: Characterizing the genetic/clinical profile of patients diagnosed with Phenylketonuria in Alagoas, monitored by the National Program of Newborn Screening. METHODS: Patients with phenylketonuria, assisted by the Reference Center for Neonatal Screening of Alagoas, underwent blood sampling for detecting genetic determinants for the phenotypic variability of the disease. Concomitantly, patients or their guardians answered a standardized questionnaire for collection of clinical and epidemiological data. RESULTS: Twenty patients (14 males and 6 females), belonging to 18 families, were monitored. Age ranged from 3-31 (mean age 10.35).We found parental consanguinity in 3/18 families; familial recurrence was 3/18; 3/20 had late diagnosis; 2/20 interrupted treatment for some time; 1/20 did not adhere to treatment; and 6/20 had clinical manifestations. Analysis of mutations was concluded in 15/20 patients. Mutations found in the phenylalanine hydroxylase gene were: R261Q-homozygous (2 patients); V388M/I65T (1); R270K/V388M (1); I65T/L348V (1); IVS10nt11G>A-homozygous (2); V388M/R252W (1); R261Q/I65T (1); IVS10nt11G>A/R252W (1); V388M/IVS10nt11G>A (3); R261Q/R252W (1); R261Q/V388M (1). CONCLUSIONS: V388M/IVS10nt11G>A was the most prevailing genotype. Thirty percent of patients were symptomatic, probably due to the nature of mutations, non-adherence to treatment, inadequate treatment and/or late diagnosis.