Mitochondrial DNA Haplogroups and Age-Related Maculopathy

Abstract

To investigate whether mitochondrial haplogroups are associated with age-related maculopathy (ARM). We assessed the association between mitochondrial haplogroups and ARM in a population-based sample of 3509 persons aged 49 years or older residing west of Sydney. Retinal photographs of both eyes were taken (1999-2001) and subsequently graded for ARM following the Wisconsin grading system. Genetic analysis for mitochondrial DNA haplogroups was performed. Associations between these genetic markers and risk factors for ARM were assessed. After adjusting for age, sex, and smoking, haplogroup H was associated with a reduced prevalence of any (early and late) ARM (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.58-0.97), early ARM (OR, 0.75; 95% CI, 0.57-0.98), and large distinct and indistinct soft drusen (OR, 0.70; 95% CI, 0.56-0.89). Haplogroup J was associated with a higher prevalence of large, soft distinct drusen (OR, 1.80; 95% CI, 1.18-2.73). Haplogroup U was associated with an increased prevalence of retinal pigment abnormalities (OR, 1.45; 95% CI, 1.11-1.91). Our findings of associations between different haplogroup types and prevalent ARM or ARM lesions suggest that these haplogroups may be genetic markers indicative of an individual's susceptibility to ARM.