 A low level expression of an MBL1 pseudogene 1 (MBL1P1) was detected in liver.The pseudogene encodes a truncated 51-amino acid protein that is homologous to the MBLA isoform in rodents and some primates.Structural mutations in exon 1 of the human MBL2 gene, at codon 52 (Arg to Cys, allele D), codon 54 (Gly to Asp, allele B) and codon 57 (Gly to Glu, allele C), also independently reduce the level of functional serum MBL by disrupting the collagenous structure of the protein.