Mannose-binding lectin haplotypes may be associated with cerebral palsy only after perinatal viral exposure

OBJECTIVE: The objective of the study was to investigate the associations between infection, polymorphisms in the mannose-binding lectin gene (MBL), and cerebral palsy (CP). STUDY DESIGN: This was a case-control study using deoxyribonucleic acid from newborn screening cards of 443 Caucasian CP cases and 883 Caucasian controls to screen for 6 polymorphisms within the MBL gene. These polymorphisms combine to create haplotypes with high (HYPA), intermediate (LYQA, LYPA), low (LXPA), and defective (HYPD, LYQC, LYPB) circulating MBL levels. RESULTS: X Analyses demonstrated significant differences between CP cases and controls (less than 37 weeks chi(2) 14.99, P = .02; less than 32 weeks chi(2) 13.62, P = .02). The MBL haplotype LYPA was associated with CP at all gestations (odds ratio [OR] 1.57, 95% confidence interval [CI], 1.00 to 2.46), less than 37 weeks (OR 2.43, 95% CI, 1.41 to 4.18), and less than 32 weeks (OR 2.54, 95% CI, 1.34 to 4.76). LYPA was also associated with hemiplegic CP for babies born at less than 37 weeks (OR 2.77, 95% CI, 1.02 to 7.26) and less than 32 weeks (OR 4.48, 95% CI, 1.55 to 12.65). HYPD was associated with quadriplegic CP at all gestations (OR 3.47, 95% CI, 1.41 to 8.31) as well as for babies born at less than 32 weeks (OR 7.86, 95% CI, 1.67 to 29.48). Subanalysis on samples previously testing positive for exposure to viral infection demonstrated similar patterns of significance as those presented above, whereas analysis on samples negative for exposure to viral infection showed no positive associations between any of the MBL haplotypes and CP. Potential type I error from multiple analyses is a caveat. CONCLUSION: MBL haplotypes LYPA or HYPD may be associated with an increased risk of CP in the presence of exposure to viral infection and may act as susceptibility factors for CP.