Bipolar risk boosted by accumulation of rare versions of genes

kb_bipolar_graph_freeRISING RISK  People with bipolar disorder are more likely than others to have several rare versions of genes that control how much nerve cells fire. Width of the shapes in the graph indicate how many people in each group had a given number of rare gene types.

A buildup of rare versions of genes that control the activity of nerve cells in the brain increases a person’s risk for bipolar disorder, researchers suggest in a paper posted online the week of February 16 inProceedings of the National Academy of Sciences.

“There are many different variants in many different genes that contribute to the genetic risk,” says coauthor Jared Roach, a geneticist at the Institute for Systems Biology in Seattle. “We think that most people with bipolar disorder will have inherited several of these risk variants.