Fainting also called as vasovagal syncope is a brief loss of consciousness when human body reacts to certain triggers, such as emotional distress or the sight of blood. A new research suggests that fainting has a strong genetic predisposition and some people may be genetically predisposed to fainting.
Researchers from American Academy of Neurology found that fainting has a strong genetic constituent and it could be inherited but not typically by a single gene. For their study researchers gave fifty sets of twins of the same gender between the age group of nine and sixty-nine s of nine and a telephonic survey.
In all study participants at least one of the twins had a history of fainting. Researchers also collected information on whether any family history of fainting. Among fifty sets of twin fifty-seven percent reported to have typical fainting simulators. The study showed that among twins where one fainted, those who were identical were nearly twice as likely to both faint compared to fraternal twins.
Identical twins were those who were born from the same fertilized egg and fraternal twins were those who born from two different fertilised eggs. The study also showed that the risk of fainting not associated with outside factors such as dehydration was also much higher in identical twins in comparison to fraternal twins.
In addition to that identical twins were much more likely to both experiences fainting related to typical stimulators than fraternal twins. The frequency of fainting in non-twin relatives was low, which suggests that the manner in which fainting is inherited is usually not by a single gene.
Lead researcher Samuel F Berkovic from the University of Melbourne in Victoria, Australia, and a member of the American Academy of Neurology, explained the question of whether fainting is caused by genetic factors, environmental factors or a mixture of both has been the subject of debate.
The study findings suggest that while fainting seems to have a strong genetic component, there may be multiple genes and multiple environmental factors that influence the phenomenon, added F Berkovic. The study was published in the medical journal of the American Academy of Neurology.