14 Feb 2016
February 15, 2016. Lithium is a first-line treatment for bipolar disorder but only works well for about one-third of patients. The variation in response is partly due to genetic factors.
Now, in a large study published in The Lancet on January 21, investigators in the International Consortium on Lithium Genetics (ConLiGen) have reported finding genetic signals on chromosome 21 that affect lithium response.
The investigators compared the lithium response score and genetic differences at six million places in the genomes of 2,563 patients.
Further support for the results came from a small treatment trial of 73 patients treated with lithium for up to two years. The patients with the "poor responder" gene variants showed a quicker relapse after lithium treatment.
The clinical utility of the finding may be limited, because the vast majority (94 percent) of people carry the responder version of the gene. However, Anil Malhotra of Zucker Hillside Hospital in Glen Oaks, New York, who was not involved in the study, told SRF, "The positive lesson is that these kinds of strategies can work for complex drug-response phenotypes, albeit probably with larger sample sizes." (For more details, see the related news story.)—Pat McCaffrey.