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Copy number variation in the complement factor H-related genes and age-related macular degeneration

Katharina E Kubista1, Nirubol Tosakulwong, Yanhong Wu

  • 1Department of Ophthalmology, Ludwig Boltzmann Institute for Retinology and Biomicroscopic Lasersurgery, Rudolf Foundation Clinic, Vienna, Austria. kubista@proeyes.at

Molecular Vision
|August 19, 2011
PubMed

Insights

A specific deletion in complement genes CFHR3 and CFHR1 offers protection against developing age-related macular degeneration (AMD). This finding highlights the role of copy number variation in AMD risk.

Area of Science:

  • Genetics
  • Ophthalmology
  • Immunology

Background:

  • Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults.
  • The complement system, particularly the regulation of complement activation (RCA) locus, plays a role in AMD pathogenesis.
  • Copy number variations (CNVs) in complement genes are increasingly recognized as potential risk factors for AMD.

Purpose of the Study:

  • To investigate the contribution of CNVs within the RCA locus to the development of AMD.
  • To quantify specific CNVs in genes including CFH, CFHR3, CFHR1, CFHR4, CFHR2, and CFHR5.

Main Methods:

  • Developed a multiplex ligation-dependent probe amplification assay for quantifying CNVs.
  • Genotyped 813 subjects (451 with AMD, 362 without AMD) for CNVs in RCA locus genes.
  • Evaluated the association between observed CNVs and AMD risk.

Main Results:

  • Observed eight unique CNV combinations across the studied genes.
  • A combined deletion of CFHR3 and CFHR1 was found to be protective against AMD (OR=0.47).
  • This protective deletion was more frequent in individuals without AMD compared to those with AMD.

Conclusions:

  • CNVs in CFHR3, CFHR1, CFHR4, and CFHR2 were identified.
  • Combined deletion of CFHR3 and CFHR1 is associated with a reduced risk of developing AMD.
  • Other observed deletions were too rare to demonstrate a statistically significant impact on AMD risk.
Abstract

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