Figure 1. Multiplex ligation probe amplification strategy to quantify copy number variation across the regulation of complement activation locus, which is shown in panel A. It comprises complement factor H (CFH) and the five CFH related genes (CFHR1–CFHR5). Panels B to H describe the MLPA assays. The forward primer (FWP) is attached to the left oligonucleotide (LO), while the right oligonucleotide (RO) is attached to the reverse primer (RVP). The oligonucleotide pairs were designed to hybridize specifically to intron 1 of CFH (B), exon 18 of CFH (C), exon 3 of CFHR3 (D), exon 3 of CFHR1 (E), exon 2 of CFHR4 (F), intron 3B of CFHR2 (G), and exon 7 of CFHR5 (H). Capital letters in the wild-type sequence from the National Center for Biotechnology Information (NCBI) correspond to exons, while lower case indicates introns. The MLPA procedure was described previously [12].