Fainting, also called vasovagal syncope (by about five neurologists and no one else), is a brief loss of consciousness that occurs when blood flow to the brain drops. Its causes are so numerous that it is basically unknown what causes it - everything from dehydration to medications to pregnancy, heart conditions and age - but these triggers all occur among people who have a strong genetic predisposition, according to new research.
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.
"The question of whether fainting is caused by genetic factors, 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. "Our results suggest that while fainting appears to have a strong genetic component, there may be multiple genes and multiple environmental factors that influence the phenomenon."
Published in Neurology®
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Case For Moon: Gateway For Open Ended, Exploraton, With Planetary Protection Central - On The SpaceShow
- Sweet Irony: The Environmental Impacts Of GMO Sugar Science Denial
- Why We Get Tired When We Stay Up Too Late
- When It Comes To Replicating Psychology Studies, Good Luck
- Evidence Of Link Between Childhood Cancer And Phototherapy For Jaundice Examined
- Sexual Harassment in Science What Have We Learned (OP ED)
- Mass Killings: Extremism Or Insanity?
- "The one constant danger I've heard from those in the know about the moon is the silica dust that..."
- "Hi Kurtis,Yes, asteroids are good also. When you read the book you'll find that I make the same..."
- "Yeah. Thing about that is, anything you can find on the Moon can be found on an asteroid. Without..."
- "A generalization of the Golden Rule! ..."
- "Are you ever going to get a job, or is part of your therapy spamming and trolling people who actually..."
- New method gives scientists a better look at how HIV infects and takes over its host cells
- Current screening methods miss worrisome number of persons with mild cognitive impairment
- Couples study ties anger to heart problems, stonewalling to back pain
- Northern invaders threaten Antarctic marine life
- Even light drinkers should watch for fatty liver disease