September 22, 2019  |  

Recurrent structural variation, clustered sites of selection, and disease risk for the complement factor H (CFH) gene family.

Authors: Cantsilieris, Stuart and Nelson, Bradley J and Huddleston, John and Baker, Carl and Harshman, Lana and Penewit, Kelsi and Munson, Katherine M and Sorensen, Melanie and Welch, AnneMarie E and Dang, Vy and Grassmann, Felix and Richardson, Andrea J and Guymer, Robyn H and Graves-Lindsay, Tina A and Wilson, Richard K and Weber, Bernhard H F and Baird, Paul N and Allikmets, Rando and Eichler, Evan E

Structural variation and single-nucleotide variation of the complement factor H (CFH) gene family underlie several complex genetic diseases, including age-related macular degeneration (AMD) and atypical hemolytic uremic syndrome (AHUS). To understand its diversity and evolution, we performed high-quality sequencing of this ~360-kbp locus in six primate lineages, including multiple human haplotypes. Comparative sequence analyses reveal two distinct periods of gene duplication leading to the emergence of four CFH-related (CFHR) gene paralogs (CFHR2 and CFHR4 ~25-35 Mya and CFHR1 and CFHR3 ~7-13 Mya). Remarkably, all evolutionary breakpoints share a common ~4.8-kbp segment corresponding to an ancestral CFHR gene promoter that has expanded independently throughout primate evolution. This segment is recurrently reused and juxtaposed with a donor duplication containing exons 8 and 9 from ancestral CFH, creating four CFHR fusion genes that include lineage-specific members of the gene family. Combined analysis of >5,000 AMD cases and controls identifies a significant burden of a rare missense mutation that clusters at the N terminus of CFH [P = 5.81 × 10-8, odds ratio (OR) = 9.8 (3.67-Infinity)]. A bipolar clustering pattern of rare nonsynonymous mutations in patients with AMD (P < 10-3) and AHUS (P = 0.0079) maps to functional domains that show evidence of positive selection during primate evolution. Our structural variation analysis in >2,400 individuals reveals five recurrent rearrangement breakpoints that show variable frequency among AMD cases and controls. These data suggest a dynamic and recurrent pattern of mutation critical to the emergence of new CFHR genes but also in the predisposition to complex human genetic disease phenotypes.

Journal: Proceedings of the National Academy of Sciences of the United States of America
DOI: 10.1073/pnas.1717600115
Year: 2018

Read Publication

Talk with an expert

If you have a question, need to check the status of an order, or are interested in purchasing an instrument, we're here to help.