Extensive genomic and functional polymorphism of the complement control proteins.

Using combinations of genomic markers, we describe more than 20 distinct ancestral haplotypes (AH) of complement control proteins (CCPs), located within the regulators of complement activation (RCA) alpha block at 1q32. This extensive polymorphism, including functional sites, is important because CCPs are involved in the regulation of complement activation whilst also serving as self and viral receptors. To identify haplotypes, we used the genomic matching technique (GMT) based on the pragmatic observation that extreme nucleotide polymorphism is packaged with duplicated sequences as polymorphic frozen blocks (PFB). At each PFB, there are many alternative sequences (haplotypes) which are inherited faithfully from very remote ancestors. We have compared frequencies of RCA haplotypes and report differences in recurrent spontaneous abortion (RSA) and psoriasis vulgaris (PV).