Abstract
Purpose:
Iron is essential in normal retinal function with the highest levels in the choroid, RPE, and photoreceptors. Tissue iron levels increase with age, including the macula. Hereditary hemochromatosis is the most prevalent iron overload disease in humans with patients having a mutation in the HFE gene. HFE is also expressed in the RPE. Mutation in the HFE gene is found in approximately 10% of the general population. We investigate the prevalence of the C282Y mutation, the most common mutation, in the HFE gene in patients with age-related macular degeneration.
Methods:
Blood samples from AMD patients and control patients who do not have AMD sixty years or older were collected. Patient age, gender, race, wet versus dry AMD, and presence or absence of diabetes mellitus was compared. Blood samples were centrifuged to obtain leukocyte DNA for polymerase chain reaction for detection of the C282Y mutation in the HFE gene. Absence, heterozygosity, or homozygosity of the mutation were recorded and then compared.
Results:
A total of 82 dry AMD, 69 wet AMD, and 70 control patients were enrolled. Age and sex were statistically equal among the three groups. Prevalence of the C282Y mutation in the HFE gene was 18% in the dry AMD patients, 9% in the wet AMD patients, and 11% in the control patients. Prevalence of the mutation in the dry AMD patients was statistically significant compared to both the wet AMD and control patients.
Conclusions:
The control population has similar prevalence of the C282Y mutation as the known prevalence in the general population. The wet AMD and control patients had similar prevalence of the mutation while the dry AMD patients had a nearly 2:1 prevalence when compared to the other two groups. Retinal iron overload may play a role in the pathogenesis of AMD, specifically the dry form. Screening for the HFE mutation may serve as a tool in identifying those patients at risk for advanced atrophic AMD.
Keywords: 412 age-related macular degeneration •
539 genetics •
688 retina