Variation within the mitochondrial genome at NADH ubiquinone oxidoreductase chain 2 (MTND2 A4917G) has been reported to confer increased risk associated with AMD [19,20] and as such would provide an excellent biologic candidate of functional significance, although subsequent replication and validation in independent cohorts is necessary. This evidence concerns the gene MT-ND2 and age-related macular degeneration.