Frequência da deficiência de glicose-6-fosfato desidrogenase (G-6-PD) e sua relação com a icterícia neonatal

Abstract

Abstract Glucose-6-phosphate dehydrogenase (G-6-PD) deficiencyis the most common enzyme deficiency with its main clinicalmanifestations being hemolysis induced by drugs and neonataljaundice. The aim of this study was to investigate the frequencyof G-6-PD deficiency in newborns and verify its relationshipwith neonatal jaundice. A total of 450 blood samples of full-termnewborns that presented with jaundice within the first week oflife were analyzed, including 400 umbilical cord blood samples(Group I) and 50 peripheral blood samples (Group II). All ofthem originated from Public Healthcare Clinics of Natal, Rio Gran-de do Norte, Brazil. The methemoglobin reduction test (Brewer'stest) was carried out for all blood samples. Deficiency wasconfirmed by quantitative spectrophotometric assay for enzymeactivity and cellulose acetate electrophoresis in order to assessthe G-6-PD variant. Eight G-6-PD deficient individuals werediagnosed among the 400 cord blood samples giving a frequencyof 2%. Among boys, the frequency was 3.9% but no deficientgirls were identified. Four neonates (50%) with G-6-PD deficiencysuffered jaundice within the first 48 hours of life. All of themdeveloped moderate jaundice showing bilirubin levels higher than10.0 mg/dL. Of the 50 newborns that presented with jaundice inthe first week of life, the frequency of G-6-PD deficiency was 8%(4/50). All G-6-PD-deficient neonates (Groups I and II) had anAfrican variant (G6PD A-). The results of this study confirmedthe association between G-6-PD deficiency and neonatal jaundice.Precocious diagnosis of the deficiency through neonatal screeningis essential to control jaundice and to prevent exposure of thesenewborns to known hemolytic agents.