In cooperation with the University of Bonn, researchers studied a total of 400,000 people
Genetic factors contribute significantly to the development of bipolar disorder. The probably largest analysis to date on the hereditary factors involved has now been published. More than 40,000 affected individuals and 370,000 controls were included in the study; some 320 researchers around the globe were involved. Lead partners for the project included the Icahn School of Medicine, New York, the University of Oslo and the University Hospital Bonn. The results not only provide new insights into the genetic basis of the disease, but also into possible risk factors in living conditions or behavior. They are published in the journal "Nature Genetics".
The name "bipolar disorder" is not a coincidence: The mood of those affected oscillates between two extremes. Sometimes they are so depressed for weeks that they barely manage to go about their daily activities. At other times, there are phases when they feel euphoric and full of energy, frantically pursuing their projects.
Risk factors include early childhood traumas such as abuse or the loss of a parent, but also, for example, a stressful lifestyle or the use of certain drugs. To a large extent, however, bipolar disorder is a matter of genes: Experts estimate the contribution of genetic makeup at 60 to 85 percent. Hundreds of genes are probably involved.
DNA lexicon compared at hundreds of thousands of sites
This greatly improves the understanding of the genetic basis. The international consortium searched the DNA of more than 400,000 participants for abnormalities. By comparing the DNA of their subjects at many hundreds of thousands of sites that occur variably in the population, they were able to identify genetic regions that are thought to contribute to the disease. "In this way, we identified 64 gene loci associated with bipolar disorder," explains Prof. Dr. Markus Nöthen, head of the Institute of Human Genetics and meme of the Cluster of Excellence ImmunoSensation2. "33 of them were previously unknown." The hits thus also provide clues to new therapeutic approaches.
Niamh Mullins, Andreas J. Forstner et al.: Genome-wide association study of more than 40,000 bipolar disorder cases provides new insights into the underlying biology. Nature Genetics, DOI: 10.1038/s41588-021-00857-4