Monday, December 6, 2010

Gene Duplication and Depression

This is unexpected again, although hindsight tells us that the pattern is certainly prospective of genetic oddity.

This does not apply to depression caused by physical exhaustion which is the common form and that includes emotional exhaustion which surely disturbs the metabolism in the same way as physical exhaustion.

I suspect the genetic triggered depression also has a similar metabolic pathway.

In the event, real depression is a dangerous malady and a sufferer often needs medical treatment,   I suspect all forms of depression can generate the maximum symptoms and those are surprising the first time encountered.  I had one such encounter in my life when young and that was scary enough to ensure tight personal control over any driving circumstances.  When a person realizes that your own mind and biochemistry can play you it is not too hard to impose discipline that prevents it.

Unfortunately many look to chemical solutions.  Getting annoyed is a better solution as well as simply engaging in social activity to distract the mind.  Yet it is hard to query your own responses to stimuli objectively and more so to learn how to do so.

Just as you must ask why you are suddenly angry, when in another circumstance no such thing would have occurred, you must ask why you are unhappy.  The reality is that we are hugely affected by blood sugar balances in particular and that is controlled by sleep and cumulative wok and cumulative emotional stress.

It would be wonderfully beneficial if we could devise a monitoring device on our cell phone that tracked our biochemistry and informed us when we increasingly vulnerable and to take evasive action.  It may well be possible and it may be readily applied to others on demand.  I think this is one toy our civilization actually could use.

Released: 11/30/2010 5:20 PM EST 

--Finding by CHOP Researchers Points to Disruptions in Brain Signaling Networks--
Newswise — A large genetic study of people with major depression has found that a duplicated region of DNA on chromosome 5 predisposes people to the disorder. The gene involved plays an important role in the development of nerve cells, adding to evidence that disruptions in neurotransmission networks form a biological basis for depression.

“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,” said study leader Hakon Hakonarson, M.D., Ph.D., director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia. “This finding extends work by other researchers suggesting that disruptions in neurotransmitter networks in the brain are an underlying cause of major depressive disorders.”

The study appears online today in Public Library of Science One (PLoS One).

The current research is the first large-scale genome-wide study of copy number variation (CNV) in major depressive disorder (MDD), a major psychiatric and behavioral disorder affecting an estimated 16 percent of the U.S. population. CNVs are deletions or duplications of segments of DNA. While a specific CNV is relatively rare in a population, it often exerts a strong effect on an individual who harbors the CNV in their genes.

Hakonarson’s group conducted a whole-genome scan of DNA from 1,693 patients with MDD, mainly from a European database, and from 4,506 control subjects.

The researchers identified 12 CNVs exclusive to MDD cases. Their most notable finding was a large duplication of DNA segments on chromosome 5q35.1, a CNV shared by five unrelated patients and not observed in healthy controls. Residing at that location is the gene SLIT3, which is involved in axon development. The axon is the portion of a neuron that carries nerve impulses away from the cell body.

Hakonarson added that he plans follow-up studies with more refined sequencing technology, in which he expects to identify many more CNVs and possibly other types of mutations in the SLIT3 gene, as well as in other functionally related genes that may predispose to depression. Further studies may also reveal how strongly CNVs at SLIT3 and other related genes contribute to the risk of depression.

“Clinical applications for our discoveries are still in the future, but it may be possible at some point to incorporate these findings into personalized medicine,” Hakonarson said. “Identifying causative genes may suggest future targets for drug development, and may also help us predict a person’s future risk of developing depression,” he added.

Hakonarson’s group used genotype data from the Genetic Association Information Network and from the database of Genotype and Phenotype (dbGaP) of the National Institutes of Health. Funding for the study came from an Institutional Development Award from The Children’s Hospital of Philadelphia and from a Research Development Award from the Cotswold Foundation.

“Duplication of the SLIT3 Locus on 5q35.1 Predisposes to Major Depressive Disorder,” PLoS One, published online Dec. 1, 2010.

About The Children’s Hospital of Philadelphia: The Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children’s Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking third in National Institutes of Health funding. In addition, its unique family-centered care and public service programs have brought the 460-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit

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