- Factor H mutations in hemolytic uremic syndrome cluster in exons 18-20, a domain important for host cell recognition. Richards, A., Buddles, M.R., Donne, R.L., Kaplan, B.S., Kirk, E., Venning, M.C., Tielemans, C.L., Goodship, J.A., Goodship, T.H. Am. J. Hum. Genet. (2001)