Surfactant Protein B Allelic Polymorphism and RDS in Preterm Neonates

Abstract

Pulmonary Surfactant components play important roles in normal lung function. SP-B gene is known to be polymorphic and the presence of polymorphisms has been implicated in RDS. The aim of this study was to elucidate the association between C1580T SP-B gene polymorphism and RDS among preterm neonates with special emphasis on its impact on clinical status of the disease, severity and outcome. The possibility of using it as a marker in population and family base association studies. Subject & methods:40 RDS preterm neonates ,40 healthy preterm controls and 40 fullterm neonates controls were genotyped using Allelic discrimination assay of SP-B C1580T by polymerase chain reaction (PCR) and Restriction enzyme fragment length polymorphism (REFLP). Results: The frequency of C allele of SP-B was significantly higher in RDS patients than in controls with an OR=4.5, CI=2.65-7.62, p=0.0001.Genotypic analysis revealed that CC genotype frequencies were higher in RDS patients (37.5%) than preterm controls (12.5%) with a high statistical significant association (P=0.0001). CC genotype is more prevalent in males than females and in those with positive family history showing a statistical significant association (p<0.05). Moreover, it was significantly associated with disease severity (p=0.04) and with adverse outcome (p=0.02).While TT and CT genotypes were more prevalent among controls with a high statistical significant association (p=0.0001).Conclusion: Higher frequency of genotype CC among RDS patients suggesting that genotype CC might be associated with risk for RDS development and might serve as biomarker of susceptibility of RDS. Key words: Respiratory distress syndrome, SP-B, Polymorphism, REFLP.