Bipolar disorder, sometimes called manic-depression, is a mental illness known to be hereditary. The condition causes wide, sometimes disabling mood swings between euphoria and depression. According to the Mayo Clinic, signs of the "manic phase" can include over-optimism, reckless judgment and behavior, racing thoughts and speech, drug abuse, increased sexual urges, poor concentration and insufficient sleep. When the pendulum swings to the bottom, sufferers may exhibit anxiety, sadness, hopelessness, guilt, poor appetite, chronic pain or fatigue, general loss of interest, and suicidal tendencies (suicide rates are high for those afflicted with the illness). Patients with very severe cases may experience hallucinations or delusions. The destructive effects of bipolar disorder can adversely affect every aspect of life, not only for the sufferer but also for family, friends and associates. Recent advances in genetic research have led to the hypothesis that multiple genes may be causing the illness.
Chromosome 22
According to the School of Medicine at the University of California--San Diego, recent research has focused on specific chromosomes as locations of the genes that cause bipolar disorder. A UCSD research team found evidence for bipolar genes on Chromosome 22 in 1997.
Gene Identified
In June 2003, the journal "Molecular Psychiatry" reported that researchers from the UCSD School of Medicine had become the first to identify a gene, associated with Chromosome 22, which causes bipolar disorder in certain patients. Their conclusions focused on mutations in a gene called G protein receptorkinase 3 (or GRK3 for short) that normally "regulates sensitivity to brain neurotransmitters such as dopamine."
Mutations Cause Malfunction
The yearlong UCSD study screened DNA in over 400 families that suffer from bipolar disorder. Six mutations were found in the GRK3 gene, one of which occurred three times more often in bipolar-disorder patients than in others. The researchers hypothesized that this mutation causes the gene to operate at the wrong times, bringing about bipolar mood swings by causing hypersensitivity to dopamine. They expressed hopes for the development of "new drugs that can be directed" to GRK and other bipolar-related genes.
New Gene Found
In 2006, researchers at University College London and the University of Aarhus in Denmark found another gene that they linked to bipolar disorder and depression. The October 2006 issue of the "American Journal of Psychiatry" indicated that the name of the gene was "Slynar," which the researchers found on Chromosome 12.
More Work Ahead
Unlike the GRK3 gene, the normal function of the Slynar gene is unknown, according to the UCL study. Like GRK3, however, Slynar does operate abnormally after mutations. The researchers planned to continue investigating the influence of Slynar malfunctions in the onset of bipolar disorder.
Goals
While these studies have identified only small pieces of what is evidently a highly complicated puzzle of genes, mutations and bipolar causation, they are important first steps in the process of mapping out an eventual comprehensive strategy for more effectively combating bipolar disorder with drugs, diet and alternative strategies.
