Pairwise linkage disequilibrium was observed between Tyr315Cys in the P2RX4 gene and Gly150Arg in the P2RX7 gene, and these two minor alleles formed a rare haplotype that was overrepresented in patients with AMD (n=17) compared with control subjects (n=3) (odds ratio 4.05, P=0.026).
Our present study shows that loss of function of the P2X7 receptor in mice induces retinal changes representing characteristics of early AMD, providing a valuable model for investigating the role of scavenger receptor function and the immune system in the development of this age-related disease.
Finally, in a mouse model of subretinal hemorrhage, photoreceptor cells degenerated through BBG-inhibitable apoptosis, suggesting that ligation of P2RX7 by extracellular ATP may accelerate photoreceptor cell apoptosis in AMD with subretinal hemorrhage.