Surfactant protein B gene polymorphism in preterm babies with respiratory distress syndrome

• Published in: Brazilian journal of medical and biological research 2011-01, Vol.44 (1), p.66-72
• Main Authors: Lyra, P P R, Diniz, E M A, Abe-Sandes, K, Angelo, A L D, Machado, T M B, Cardeal, M
• Format: Article
• Language: English
• Subjects: BIOLOGY; Case-Control Studies; Female; Genetic Markers - genetics; Genetic polymorphism; Genetic Predisposition to Disease; Genotype; Humans; Infant, Newborn; Infant, Premature; Male; MEDICINE, RESEARCH & EXPERIMENTAL; Newborn respiratory distress syndrome; Polymerase Chain Reaction; Polymorphism, Single Nucleotide - genetics; Pulmonary Surfactant-Associated Protein B - genetics; Respiratory Distress Syndrome, Newborn - genetics; Surfactant protein B
• ISSN: 0100-879X; 1414-431X; 1414-431X; 0100-879X
• DOI: 10.1590/S0100-879X2010007500147

The etiology of respiratory distress syndrome (RDS) is multifactorial and multigenic. Studies have suggested that polymorphisms and mutations in the surfactant protein B (SP-B) gene are associated with the pathogenesis of RDS. The objectives of this study were to determine and compare the frequencies of SP-B gene polymorphisms in preterm babies with and without RDS. We studied 151 neonates: 79 preterm babies without RDS and 72 preterm newborns with RDS. The following four SP-B gene polymorphisms were analyzed: A/C at -18, C/T at 1580, A/G at 9306, and G/C at nucleotide 8714. The polymorphisms were detected by PCR amplification of genomic DNA and genotyping. The genotypes were determined using PCR-based converted restriction fragment length polymorphisms. The control group consisted of 42 (53%) girls and 37 (47%) boys. Weight ranged from 1170 to 3260 g and mean gestational age (GA) was 33.9 weeks (range: 29 to 35 weeks and 6 days). The RDS group consisted of 31 (43%) girls and 41 (57%) boys. Weight ranged from 614 to 2410 g and mean GA was 32 weeks (range: 26 to 35 weeks). The logistic regression model showed that GA was the variable that most contributed to the occurrence of RDS. The AG genotype of the A/G polymorphism at position 9306 of the SP-B gene was a protective factor in this population (OR = 0.1681; 95%CI = 0.0426-0.6629). We did not detect differences in the frequencies of the other polymorphisms between the two groups of newborns.