title: Comparison of surfactant protein B polymorphisms of healthy term newborns with preterm newborns having respiratory distress syndrome.
abstract: Polymorphisms and mutations in the surfactant protein B (SP-B) gene have been associated with the pathogenesis of respiratory distress syndrome (RDS). The objective of the present study was to compare the frequencies of SP-B gene polymorphisms between preterm babies with RDS and healthy term newborns. We studied 50 preterm babies with RDS (inclusion criteria - newborns with RDS and gestational age between 28 and 33 weeks and 6 days), and 100 healthy term newborns. Four SP-B gene polymorphisms were analyzed: A/C at nucleotide -18, C/T at nucleotide 1580, A/G at nucleotide 9306, and G/C at nucleotide 8714, by PCR amplification of genomic DNA and genotyping by cRFLP. The healthy newborns comprised 42 female and 58 male neonates; 39 were white and 61 non-white. The RDS group comprised 21 female and 29 male preterm neonates; 28 were white and 22 non-white. Weight ranged from 640 to 2080 g (mean: 1273 g); mean gestational age was 31 weeks and 2 days (range: 28-33 weeks and 6 days). When white children were analyzed separately, a statistically significant difference in the G/C polymorphism at 8714 was observed between groups (P = 0.028). All other genotype frequencies were similar for both groups when sex and race were analyzed together. Analysis of the SP-B polymorphism G/C at nucleotide 8714 showed that among white neonates the GG genotype was found only in the RDS group at a frequency of 17% and the GC genotype was more frequently found in healthy term newborns. These data demonstrate an association of GG genotype with RDS.
authors.affiliation: Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil. priscilalyra@yahoo.com
authors.forename: P P R
authors.initials: PP
authors.lastname: Lyra
authors.forename: F A C
authors.initials: FA
authors.lastname: Vaz
authors.forename: P E
authors.initials: PE
authors.lastname: Moreira
authors.forename: J W
authors.initials: JW
authors.lastname: Hoffmann
authors.forename: D E
authors.initials: DE
authors.lastname: Demello
authors.forename: E M A
authors.initials: EM
authors.lastname: Diniz
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D037701:Pulmonary Surfactant-Associated Protein B / Q000235:genetics*; D012127:Respiratory Distress Syndrome, Newborn / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D037701:Pulmonary Surfactant-Associated Protein B