Figure 4.

Identification of the genomic breakpoint. (A) The breakpoint is located in a region of 193 bp (underlined) between intron 5 of CFHR1 and exon 23 of CFH. The limits of the region are identified by single nucleotide polymorphism differences between CFH and CFHR1 indicated by arrows. Black arrows indicate CFHR1-specific single nucleotide polymorphism variants, and red arrows indicate CFH-specific single nucleotide polymorphism variants. (B) NAHR occurring between CFH and CFHR1 at the positions indicated by the X results in the formation of the CFHR1/CFH hybrid gene consisting of the first five exons of CFHR1, exon 23 of CFH, and an extra copy each of CFHR3 and CFHR1 (boxed area). The duplicated region is highlighted in gray.