We hypothesized that mannose binding lectin gene(MBL2), a key molecule of innate immunity, may contirbute to the development and the outcome of respiratory syncytial virus(RSV) disease in early childhood. This study was performed to investigate the genetic basis of polymorphisms and haplotypes of MBL2 for RSV disease severity in Korean children.

Cases with severe RSV diseases are 99 children with severe RSV lower respiratory tract infections, who were admitted to the Seoul National University Children's Hospital through 1993~2000. The control subjects consisted of 224 anonymous healthy Korean blood donors. The frequency of promoter variant(−221, X/Y) and structural variant(codon 54) were compared between the case patient group and the control subject group.

The mean age of patients was 11.8 months; 49% were <6 months, 39% were 6–24 months and 12% were >24 months. In the cohort of cases of severe RSV diseases, the genotypic frequencies of structural variant in codon 54 were 61% for AA, 34% for AB, and 5% for BB. Those of the promoter X/Y variant were 85% for YY and 15% for XY. There were no significant differences in overall distribution of both structural and promoter variants between the cases and the control subjects. We did not observe statistical difference in the haplotypic frequencies of MBL2.

Common variants of MBL2 gene most likely do not contribute to the risk for severe RSV diseases in Korean children. Further genetic association studies should be conducted in a larger propsectively recruited cohort of children with RSV infection.