title: Clinical and genetic risk factors for moderate hyperbilirubinemia in Brazilian newborn infants.
abstract: OBJECTIVE
  To identify clinical and genetic risk factors for moderate hyperbilirubinemia during the first week of life.
  
  
  METHODS
  Using univariate and multivariate multiple regression analyses, the RR for clinical factors, the African variant of glucose-6-phosphate dehydrogenase (G6PD) deficiency (G202A/A376G), and (TA)(n) UGT1A1 polymorphisms were established in a cohort of 608 Brazilian newborn infants. Hyperbilirubinemia was monitored until 134.5 ± 49.8 h of life (IQR, 111.0 to 156.7). The dependent variable was total bilirubinemia (TB) ≥12.9 mg per 100 ml estimated by transcutaneous or plasma bilirubin measurements.
  
  
  RESULTS
  The African variant of G6PD deficiency and (TA)(7)/(TA)(7) and (TA)(7)/(TA)(8) polymorphisms present in 6.1 and 12.0% of newborns, respectively, were not risk factors for moderate hyperbilirubinemia. Coexpression of G6DP deficiency and UGT1A1 polymorphisms occurred in 0.49% of the subjects. Independent clinical predictors for TB≥ 12.9 mg per 100 ml were gestational age <38 weeks and reference curve percentiles >P40th.
  
  
  CONCLUSIONS
  In this study, G6PD deficiency and UGT1A1 gene promoter polymorphisms were not risk factors for moderate hyperbilirubinemia. Genetic factors may vary considerably in importance among different populations.
authors.affiliation: Division of Neonatology, Department of Pediatrics, School of Medical Sciences, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Mezzacappa
authors.forename: F P
authors.initials: FP
authors.lastname: Facchini
authors.forename: A C
authors.initials: AC
authors.lastname: Pinto
authors.forename: A E L
authors.initials: AE
authors.lastname: Cassone
authors.forename: D S
authors.initials: DS
authors.lastname: Souza
authors.forename: M A C
authors.initials: MA
authors.lastname: Bezerra
authors.forename: D M
authors.initials: DM
authors.lastname: Albuquerque
authors.forename: S T O
authors.initials: ST
authors.lastname: Saad
authors.forename: F F
authors.initials: FF
authors.lastname: Costa
mesh_terms: D001938:Brazil; D015331:Cohort Studies; D003431:Cross-Cultural Comparison; D005260:Female; D005500:Follow-Up Studies; D006580:Genetic Carrier Screening; D005838:Genotype; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000175:diagnosis / Q000235:genetics; D014453:Glucuronosyltransferase / Q000235:genetics; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000175:diagnosis* / Q000235:genetics*; D007231:Infant, Newborn; D007647:Kernicterus / Q000175:diagnosis / Q000235:genetics; D008297:Male; D015997:Neonatal Screening; D011110:Polymorphism, Genetic / Q000235:genetics; D011446:Prospective Studies; D012307:Risk Factors; D000099148:UGT1A1 Enzyme
chemical_list: D014453:Glucuronosyltransferase; D000099148:UGT1A1 Enzyme