Protein May Increase Risk of Inherited Bipolar Disorder

A brain protein known as PCLO (pronounced piccolo) may increase risk of inheriting bipolar disorder, according to a new study.

The Piccolo protein, located at the endings of nerve cells, contributes to the ability of nerve cells to release chemical messengers.

Researchers compared gene-expression patterns in postmortem brain tissue in bipolar patients to tissue from people who did not have psychiatric illnesses prior to their death. They were able to identify 45 genes and genetic variations that altered mRNA levels considerably. The researchers then used this information to hone in on part of the genome they wanted to explore.

The team then tested genetic markers that were close to the altered expression levels in the tissue and found Piccolo, a variation of which appeared to contribute to the risk of bipolar disorder. The discovery could yield new, better targeted treatments for the disorder.

Bipolar disorder is characterized by manic mood shifts -- from thrilling highs to crushing lows. Lithium is often prescribed for bipolar patients, in combination with psychotherapy.