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Complement factor B polymorphism and the phenotype of early age-related macular degeneration

Irmela Mantel1, Aude Ambresin, Leila Moetteli

  • 1Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital , Switzerland , and.

Ophthalmic Genetics
|February 5, 2013
PubMed

Insights

The CFB (R32Q) gene variant is linked to smaller drusen in age-related macular degeneration (AMD). This finding suggests a protective role against larger drusen and increased peripheral drusen in AMD patients.

Area of Science:

  • Ophthalmology
  • Genetics
  • Molecular Biology

Background:

  • Age-related macular degeneration (AMD) is a leading cause of vision loss.
  • Polymorphisms in complement pathway genes are associated with AMD.
  • Complement factor B (CFB) is implicated in AMD pathogenesis.

Purpose of the Study:

  • To investigate the genotype-phenotype correlation of CFB (R32Q) polymorphisms in Caucasian AMD patients.
  • To assess the association between CFB (R32Q) and specific phenotypic features of early AMD.

Main Methods:

  • Analysis of a Central European cohort of 349 early AMD patients.
  • Classification of early AMD based on drusen size, surface area, location, and pigmentary changes.
  • Statistical evaluation of CFB (R32Q/rs641153) association with AMD phenotypes, adjusted for age, sex, CFH, and ARMS2 polymorphisms.

Main Results:

  • CFB (R32Q) polymorphism significantly associated with smaller drusen size (largest ≤ 250 µm, predominant ≤ 125 µm).
  • Association found with smaller drusen-covered surface area (≤ 10%) and more frequent peripheral drusen.
  • No association observed between CFB (R32Q) and pigmentary changes.

Conclusions:

  • CFB (R32Q) polymorphism is linked to AMD characterized by small drusen.
  • This polymorphism appears protective against large drusen and extensive drusen coverage.
  • Increased prevalence of peripheral drusen observed, supporting the role of complement in AMD pathogenesis.
Abstract

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