Imprinted and More Equal
15 March 2007: An epigenetic change alters the phenotype without changing the genotype. As a result of their unique genetic make-up, imprinted genes act as nodes of susceptibility for asthma, cancer, diabetes, obesity and many behavioral and developmental disorders - a list that is surprisingly long given the limited number of imprinted genes identified so far. The potential for malign influence at these sites is disproportionately large. In this respect, they're similar to the tyrannical pigs in George Orwell's Animal Farm, who famously declared, "all animals are equal, but some animals are more equal than others." The same is true for genes, and it's often the imprinted genes that are "more equal" in the formation of human diseases.