A novel deletion including CFHR1 and CFHR4. Position of the genes encoding factor H and the factor H–related proteins in a centromeric segment of the RCA cluster at 1q32. Regions of high sequence identity (originally determined by Male et al²⁰ ) are indicated by the same letter and color. Exons are indicated as vertical lines. The shaded box shows the presence of a novel ∼ 125-kb deletion, which includes CFHR1 and CFHR4. This deletion occurs within the duplicons C/C′ as a result of nonallelic homologous recombination.