Accumulated Mutations Create A Cellular Mosaic In Our Bodies

"Your body has about 40 trillion cells, and they all arose from a single fertilized egg. But it turns out the DNA in many of those cells is no longer a perfect clone of that original one."

"A study published Thursday in the journal Science shows that our body's cells are a mosaic, with many subtle genetic variations."

"It's not news that that our cells pick up mutations as we age. Some skin cells morph into moles. And scientists have previously documented widespread genetic changes in cells in the skin, esophagus and blood."

"Tumors start out as mutant cells, as well."

"'But no one has really characterized this across many different tissues and across a great amount of individuals,' says Keren Yizhak. She took that as a challenge as she started working as a postdoctoral researcher at the Broad Institute at MIT and Harvard."

"She and her colleagues tapped into genetic information from about 500 people, cataloging 29 different tissues. They found populations of mutant cells in just about everyone they studied."

"'The skin, the lung and the esophagus were the ones where we found the highest amount of mutations,' she says."