"We have traced the biological origins of AMD back to an innate immune system response to an infection early in life," says Rando Allikmets, Ph.D., Director of Research at Columbia University's Harkness Eye Institute. Allikmets and an international team of researchers discovered that two gene variants—Factor H and Factor B, each with protective and risk-increasing variants—play a role in regulating the body’s immune system machinery.

"This immune response, combined with a few tiny genetic variations, can trigger a chain of events that eventually leads to AMD later in life," explains Allikmets. Seventy-four percent of the study's subjects with AMD had either the Factor H or the Factor B risk variant (or both), but no protective variants of either gene. "It is likely that the Factor H risk variant developed as a function of geographic location and natural selection as a strong immune response to certain pathogens. While it is good for survival at an early age—during the reproductive stage of one's life—it also results in chronic inflammation in the eye at a very advanced age, when natural selection does not apply."

Back to Health Connections