Epigenetic changes are heritable changes to the regulation of a cell's genes, caused by extra molecules being attached to those genes.

Because of the complementary roles of the these two genes, a protective Factor B variation can protect against AMD, even if one carries a risk-increasing variant of Factor h, and vice versa.

Nanjing 210009; 2Gene Diagnosis and CytotherapeuticsLaboratory of the Second Hospital in Nanjing Affiliated to Southeast University;