In dengue and DWS patients, allele MBL2*Y at the promoter region and allele MBL2*A at codons 52 + 54 + 57 significantly contributed to higher MBL levels, whereas alleles MBL2*X and MBL2*O contributed to lower MBL levels (P < 0.05). The gene discussed is MBL2; the disease is dengue disease.