The research revealed that, with diseases, "it's not necessarily the gene but probably a network of genes that are working together," and these "switches" or "regulatory" DNA orchestrate entire networks, Stamatoyannopoulos said.
The authors of an accompanying editorial agreed that the finding could shed light on disease mechanisms.
"Many of these variations in DNA that are associated with disease are not directly affecting protein sequences," explained Eric Schadt, co-author of the accompanying perspective and chairman of genetics and genomic sciences at Mount Sinai School of Medicine in New York City. "They are affecting regions in the DNA that regulate whether genes should be expressed or not, and at what level. They're playing more of a regulatory role versus a protein-function role. We are able to see that loud and clear in [this] data."
Three-quarters of the diseases studied had links to regulatory DNA, and many of these aberrations were already at work in the womb.
The researchers also found that many common diseases, such as Crohn's and lupus, that seem very different, may actually share some of the same regulatory genes.
With this new information, "we can start understanding not only what disease do you have but what subtype do you have, what pathways are affected and what treatments are most beneficial for those particular subtypes," said Schadt.
"This enables us to develop a more granular view of disease, of the processes underlying disease, and that is going to enable a personalized medicine sort of approach," he added.
The Human Genome Project has more on human genetics.
SOURCES: John Stamatoyannopoulos, M.D., associate professor, departments of genome sciences and medicine, University of Washington, Seattle; Eric Schadt, Ph.D.
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