New gene linked to bipolar disorder

The collaboration, led by Professor Hugh Gurling at UCL and Professor Ole Mors at the University of Aarhus, first looked at bipolar cases in families living in the UK and in Denmark, and then at large numbers of unrelated people with bipolar disorder. The results of the genetic searches, published in the October issue of the American Journal of Psychiatry, identified the gene – known as Slynar – which is found on chromosome 12.

Bipolar disorder is known to run strongly in families, but the Slynar gene is one of just three genes now known to be implicated in susceptibility to the disorder. This gene appears to be present in around 10 per cent of bipolar disorder cases. Previous studies of families have already shown that there are multiple genetic subtypes of the disorder, but progress in identifying the exact genes responsible has been slow because groups of families inherit different susceptibility genes.

The Slynar gene is normally found in the brain, but in bipolar disorder has an abnormal effect due to mutations in the gene. However, researchers do not yet know what the gene’s normal function is or how these mutations might be contributing to the disorder.

Professor Hugh Gurling, UCL Department of Mental Health Sciences, says: “The next step is to determine the role of the Slynar gene in the brain and how abnormalities in this gene may cause bipolar disorder. Using techniques such as animal models will help us to fully understand the mechanisms behind this gene and explore how we might be able to intervene in these mechanisms, to help people with the disorder.

“We hope our discovery will eventually lead to new treatments for depression and bipolar disorder, including possible preventive strategies, for example with drugs or even through nutritional intervention.”

Around one in every 200 people in the UK develops bipolar and other related mood disorders. Signs of depression include losing weight, feeling totally negative about oneself, feel hopeless about the future and sometimes ending up in a depressive stupor in bed, unable to move, eat, drink or talk. People with bipolar disorder may also experience extreme mood highs, overactivity, increased libido, sleeplessness and grandiose delusions.