Surfactant protein A associated with respiratory distress syndrome in Korean preterm infants: evidence of ethnic difference.

BACKGROUND

Insufficiency of the pulmonary surfactant system is the primary cause of respiratory distress syndrome (RDS) in preterm infants. Genetic factors, including specific single-nucleotide polymorphisms in the genetic components of surfactant protein A (SP-A1 and SP-A2), affect protein structure and function, as well as risk of RDS.

OBJECTIVE

We investigated the association between variations in SP-A genotypes and RDS within the genetically homogeneous Korean population.

METHODS

We used TaqMan® real-time polymerase chain reaction technology to assess nine single-nucleotide polymorphisms of SP-A in 261 full-term and 152 preterm infants. Among the preterm infants, 76 infants with RDS were matched with 76 control infants with respect to gestation, use of antenatal steroids and gender.

RESULTS

The SP-A2 1A(0) variant and the homozygous 1A(0)/1A(0) genotype were associated with protection from RDS (OR 0.31, 95% CI 0.13-0.78). In addition, the 1A(1) carrier genotype (containing one copy of the 1A(1) variant) was associated with increased risk of RDS (OR 2.42, 95% CI 1.06-5.52). The significance of these results is that the association of patterns with RDS was opposite to the findings of previous research with Finnish and North American study populations.

CONCLUSIONS

We have identified associations between specific variants of the SP-A genes and RDS risk in the Korean preterm study population. Our data strongly support SP-A as a candidate gene for susceptibility to RDS, and reveal the dissimilarity of the associated risk/protective genetic variants between different ethnic study populations.