Fainting: All in the family?

August 6, 2012

Fainting has a strong genetic predisposition, according to new research published in the August 7, 2012, print issue of Neurology, the medical journal of the American Academy of Neurology. Fainting, also called vasovagal syncope, is a brief loss of consciousness when your body reacts to certain triggers, such as emotional distress or the sight of blood.

"The question of whether fainting is caused by , environmental factors or a mixture of both has been the subject of debate," said study author Samuel F. Berkovic, MD, FRS, with the University of Melbourne in Victoria, Australia, and a member of the American Academy of Neurology.

For the study, 51 sets of twins of the same gender between the ages of nine and 69 were given a telephone questionnaire. At least one of the twins had a history of fainting. Researchers also gathered information about any family history of fainting. Of the 51 sets of twins, 57 percent reported having typical fainting triggers.

The research found that among twins where one fainted, those who were identical (from the same fertilized egg) were nearly twice as likely to both faint compared to fraternal twins (those from two different fertilized eggs). The risk of fainting not related to outside factors (such as dehydration) was also much higher in identical twins compared to fraternal twins. Identical twins were much more likely to both experience fainting associated with typical triggers than fraternal twins. The frequency of fainting in non-twin relatives was low, suggesting that the way fainting is inherited is usually not by a single gene.

"Our results suggest that while fainting appears to have a strong , there may be multiple genes and multiple environmental factors that influence the phenomenon," said Berkovic.

Explore further: Study shows fainting factor in cardiac arrests

Related Stories

Study shows fainting factor in cardiac arrests

February 9, 2012
A new study by Dr. Andrew Krahn shows that over a quarter of unexplained cardiac arrests occurred after the patient had an event of fainting, known as syncope. According to Dr. Krahn, a Cardiologist at London Health Sciences ...

Recommended for you

Researchers find monkey brain structure that decides if viewed objects are new or unidentified

August 18, 2017
A team of researchers working at the University of Tokyo School of Medicine has found what they believe is the part of the monkey brain that decides if something that is being viewed is recognizable. In their paper published ...

Artificial neural networks decode brain activity during performed and imagined movements

August 18, 2017
Artificial intelligence has far outpaced human intelligence in certain tasks. Several groups from the Freiburg excellence cluster BrainLinks-BrainTools led by neuroscientist private lecturer Dr. Tonio Ball are showing how ...

Study of nervous system cells can help to understand degenerative diseases

August 18, 2017
The results of a new study show that many of the genes expressed by microglia differ between humans and mice, which are frequently used as animal models in research on Alzheimer's disease and other neurodegenerative disorders.

How whip-like cell appendages promote bodily fluid flow

August 18, 2017
Researchers at Nagoya University have identified a molecule that enables cell appendages called cilia to beat in a coordinated way to drive the flow of fluid around the brain; this prevents the accumulation of this fluid, ...

Researchers make surprising discovery about how neurons talk to each other

August 17, 2017
Researchers at the University of Pittsburgh have uncovered the mechanism by which neurons keep up with the demands of repeatedly sending signals to other neurons. The new findings, made in fruit flies and mice, challenge ...

Neurons involved in learning, memory preservation less stable, more flexible than once thought

August 17, 2017
The human brain has a region of cells responsible for linking sensory cues to actions and behaviors and cataloging the link as a memory. Cells that form these links have been deemed highly stable and fixed.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.