Genetic Variability of Complement Factor H Has Ethnicity-Specific Associations With Choroidal Thickness

Area of Science:

• Ophthalmology
• Genetics
• Population Health

Background:

• Choroidal thickness (CT) is a key indicator of ocular health.
• Genetic factors are known to influence CT, but ethnic variations require further investigation.
• Understanding these variations is crucial for studying diseases like age-related macular degeneration (AMD).

Purpose of the Study:

• To investigate the association between specific genetic alleles and choroidal thickness (CT) in a multiethnic Asian population.
• To identify genetic markers influencing subfoveal choroidal thickness (SFCT) within diverse Asian ethnic groups.
• To explore ethnic-specific genetic influences on ocular parameters.

Main Methods:

• A population-based cohort of 1045 healthy Asian individuals (Chinese, Indian, Malay) underwent spectral-domain OCT (SD-OCT) and genotyping.
• Risk alleles in CFH, VIPR2, ARMS2, and CETP genes were analyzed.
• Associations between identified alleles and subfoveal choroidal thickness (SFCT) were statistically evaluated.

Main Results:

• Several CFH alleles showed significant associations with SFCT, varying by ethnicity.
• In Indians, CFH alleles (rs800292, rs1061170, rs1329428) correlated with increased SFCT (+18.7 to +31.7 µm).
• In Malays, these alleles were marginally linked to decreased SFCT (-12.7 to -20.6 µm).
• CFH haplotype analysis revealed ethnic-specific effects, and rs1061170 was associated with reduced CT in specific sectors of the Chinese cohort.

Conclusions:

• CFH gene variants exhibit variable associations with choroidal thickness across Asian ethnic groups.
• These findings have significant implications for understanding the pathogenesis of ocular conditions like AMD and central serous choroidopathy.
• Ethnic background is a critical factor in the genetic determination of choroidal thickness.