title: Atypical hemolytic uremic syndrome and genetic aberrations in the complement factor H-related 5 gene.
abstract: Atypical hemolytic uremic syndrome (aHUS) is a severe renal disorder that is associated with mutations in genes encoding proteins of the alternative complement pathway. Previously, we identified pathogenic variations in genes encoding complement regulators (CFH, CFI and MCP) in our aHUS cohort. In this study, we screened for mutations in the alternative pathway regulator CFHR5 in 65 aHUS patients by means of PCR on genomic DNA and sequence analysis. Potential pathogenicity of genetic alterations was determined by published data on CFHR5 variants, evolutionary conservation and in silico mutation prediction programs. Detection of serum CFHR5 was performed by western blot analysis and enzyme-linked immunosorbent assay. A potentially pathogenic sequence variation was found in CFHR5 in three patients (4.6%). All variations were located in short consensus repeats that might be involved in binding to C3b, heparin or C-reactive protein. The identified CFHR5 mutations require functional studies to determine their relevance to aHUS, but they might be candidates for an altered genetic profile predisposing to the disease.
authors.affiliation: Department of Pediatric Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands. d.westra@cukz.umcn.nl
authors.forename: Dineke
authors.initials: D
authors.lastname: Westra
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Vernon
authors.forename: Elena B
authors.initials: EB
authors.lastname: Volokhina
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Pickering
authors.forename: Nicole C A J
authors.initials: NC
authors.lastname: van de Kar
authors.forename: Lambert P
authors.initials: LP
authors.lastname: van den Heuvel
mesh_terms: D000293:Adolescent; D000595:Amino Acid Sequence; D065766:Atypical Hemolytic Uremic Syndrome; D016022:Case-Control Studies; D002648:Child; D015938:Complement Membrane Attack Complex / Q000235:genetics / Q000378:metabolism*; D003170:Complement Pathway, Alternative; D003165:Complement System Proteins / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005820:Genetic Testing / Q000379:methods; D006463:Hemolytic-Uremic Syndrome / Q000235:genetics* / Q000378:metabolism; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: C432223:CFHR5 protein, human; D015938:Complement Membrane Attack Complex; C047610:SC5b-9 protein complex; D003165:Complement System Proteins