Genetic analysis of complement factor H related 5, CFHR5, in patients with age-related macular degeneration.
OBJECTIVE
To investigate the complement factor H related 5 (CFHR5) gene, encoding a member of the complement factor H family, for the presence of genetic polymorphisms or mutations associated with age-related macular degeneration (AMD).


METHODS
We screened 639 unrelated patients with AMD and 663 age-matched normal controls using direct genomic sequencing of the ten coding exons, along with the immediately flanking intronic DNA. The pathologic impact of the identified sequence variants were analyzed by computational methods using PolyPhen and PMut algorithms.


RESULTS
We identified five heterozygous sequence changes in CFHR5. Asp169Asp had a minor allele frequency of 0.001% in patients and 0.014% in controls (p<0.0001), while Arg356His had a minor allele frequency of 0.016% in patients and 0.007% in controls. Val379Leu, Met514Arg, and Cys568Ter were found only in normal controls. In silico analysis predicted Arg356His and Val379Leu to be neutral and benign. Met514Arg was predicted to be pathological and damaging to the function of the CFHR5 protein.


CONCLUSIONS
No definitive pathogenic CFHR5 mutations have been found in any of 639 unrelated patients with AMD, indicating that sequence variations in CFHR5 do not play a major role in determining AMD susceptibility. However, our findings suggest a possible protective role for Asp169Asp. Further studies of different and larger populations of patient and control samples will be required to address this observation.
Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Umadevi
U
Narendra
Gayle J T
GJ
Pauer
Stephanie A
SA
Hagstrom
D000368:Aged; D000369:Aged, 80 and over; D001798:Blood Proteins / Q000235:genetics*; D003165:Complement System Proteins; D005260:Female; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction
D001798:Blood Proteins; C432223:CFHR5 protein, human; D003165:Complement System Proteins