October 15, 2012, researchers at Kings College in London published a study in the journal Biological Psychiatry, entitled “Replication study and meta-analysis in European samples supports association of the 3p21.1 locus with bipolar disorder” Biological Psychiatry. 2012 Oct 15;72(8):645-50. Vassos E, et al.) This study replicates earlier findings that connect changes at a particular gene region on chromosome 3p21.1 to bipolar disorder.
The genetic region PBRM1 has previously been shown to be associated with a risk of bipolar disorder, and further work found connections between this region and other psychiatric disorders, including schizophrenia.
This current study, which includes high numbers of patients and healthy controls, shows a strong connection between bipolar disorder and particular genetic changes at the PBRM1 region. However, their data do not support an association of this marker with schizophrenia. This suggests that science is getting closer to pinpointing the different genes associated with bipolar and those associated with schizophrenia. (Trying to tease out the two disorders has been difficult — many of the risk genes overlap between the two disorders.)
Recognizing the biological basis of bipolar disorder and other mental illnesses is important in helping us accept the fact that mental illness is illness and not some sort of weakness in character. Fortunately, recent advances in genetic research have accelerated the pace of findings that are zeroing in on the genetic areas associated with various mental illnesses, including bipolar disorder, depression, and schizophrenia.
PBRM1 is a gene region, not one specific gene. It is not yet known how this particular genetic region relates to bipolar disorder or what epigenetic changes might be associated with triggering bipolar disorder in those with this genetic profile. (For more about epigenetics and bipolar disorder, see Dr. Fink’s post “The Effects of Chronic Stress on Bipolar Genes.”)
Defining the association between certain gene or gene regions and bipolar disorder and/or schizophrenia will be important in eventually being able to make diagnoses based on the underlying brain changes causing these conditions rather than relying only on observations of symptoms that are often nonspecific and shared by multiple disorders.