Comparison of surfactant protein B polymorphisms of healthy term newborns with preterm newborns having respiratory distress syndrome

• Main Authors: P.P.R. Lyra, F.A.C. Vaz, P.E. Moreira, J.W. Hoffmann, D.E. de Mello, E.M.A. Diniz
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2007-06-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: Polymorphisms; Surfactant protein B; Respiratory distress syndrome
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000600005

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.