The following discovery may have greater significance to physicians treating patients suffering from depression. According to a latest research, major depression patients have a duplicated region of DNA on chromosome 5. The identified gene is supposedly involved in the development of nerve cells, so disruptions in neurotransmission networks form a biological basis for depression.
The investigation was initiated to analyze copy number variation (CNV) in major depressive disorder (MDD). CNVs are known to be deletions or duplications of DNA segments. Though a specific CNV seems to be comparatively rare in a population, it brings about a strong effect on an individual who shelters them in their genes. A whole-genome scan of DNA accumulated from 1,693 patients with MDD and 4,506 control subjects was scrutinized. At the time of the research, 12 CNVs exclusive to MDD cases were registered.
“The copy number variations we discovered were exclusive to people with depression, and were located in a gene region important in signaling among brain cells. This finding extends work by other researchers suggesting that disruptions in neurotransmitter networks in the brain are an underlying cause of major depressive disorders,” quoted, Hakon Hakonarson, MD, PhD, director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia and lead investigator.
Scientists also observed a large duplication of DNA segments on chromosome 5q35.1. This CNV probably shared by five unrelated patients was not present in healthy controls. The CNV was located in the gene SLIT3 that plays a role while developing axon. During the follow-up, refined sequencing technology will be employed to find more CNVs and different types of mutations in the SLIT3 gene along with functionally associated genes predisposing to depression.
The research is published online in PLoS One.