Mannose binding lectin (MBL) genotype distributions with relation to serumlevels in UK Caucasoids

Mannose binding lectin (MBL) gene and promoter-region polymorphisms contrib ute to a reduction in the levels of circulating MBL in a number of ways. Pr omoter polymorphisms affect the levels of MBL produced, whilst structurally encoding mutations cause non-functional protein to be assembled and subseq uently degraded. MBL is important as a protein of the innate immune system in both the clearance of potential pathogens and the activation of the comp lement cascade. Using variations of SSP-PCR amplifications and SSO probing techniques, we have produced MEL-polymorphism haplotype and genotype profil es of a series of high-level MEL-producing, low-level MEL-producing and ran dom individuals taken from a population of 800 UK Caucasoid controls. Struc turally encoding mutant alleles were more frequent within the low-level pro ducing cohort when compared to both high-level producers and the randomly s elected sample. However, not all low-level producers could be accounted for by the possession of low-level encoding haplotypes. This may be due to the presence of additional, undetected polymorphisms governing MBL production, or another external factor that may influence the transcriptional regulati on of the gene.