There are not yet any tests that would predict for predisposition to bipolar disorder. Bipolar disorder does have some genetic risk established from twin studies (40-70% lifetime risk in identical twins vs. 5% in fraternal twins) compared to patterns in the general population (2% U.S. prevalence). There is not a single gene identified determining bipolar disorder, as several candidate genes have been positively identified and seem to be interactive in determining this genetic susceptibility (as well as the susceptibility in other psychiatric disorders). Additionally, complex issues related to gene expression (the switching on and off or control of genes) have been identified that contribute to the disease burden of bipolar disorder. For these reasons, there is not currently any testing that would reliably predict a genetic predisposition for bipolar disorder.