Are you prone to fainting? Well, now you have your family to blame! According to
recent research, fainting has a strong genetic predisposition.
Scientists from
American Academy of Neurology found that fainting could be a familial trait and
can be inherited. But they point out that it is not brought about by a single
gene inheritance.
Fainting, occurs when the body reacts to
external triggers, such as the sight of blood or any other emotional stress,
causing brief loss of consciousness. This condition is also called 'vasovagal
syncope'.
There has been an ongoing debate on the factors
that cause fainting - some believe it is caused by genetic factors, others
believe it is environmental, while yet others believe that it's a mixture of
both the factors.
Study author Samuel F
Berkovic of the University of Melbourne, who is also a member of the American
Academy of Neurology says that fainting has a strong genetic component and that
there are multiple genes and multiple environmental factors that influence the
condition.
51 sets of twins aged 9-69, who belonged to the
same gender and who formed the subjects of the study, were handed over a
telephone questionnaire. At least one of each twin studied harbored a history
of fainting. Family history was also taken into account. 57% of the 51 sets of
twins had the typical triggers.
The
research found that in the case of maternal twins, if one fainted chances are
that the other fainted too. However, in fraternal twins that was not the case,
especially when fainting was not associated with external factors such as
dehydration.
The study concludes that identical twins have greater chances of experiencing
fainting triggered by typical factors compared to fraternal twins. In non-twin
relatives the frequency of fainting was usually low suggesting that fainting is
not a single gene trait.
The current study has been published in the
journal Neurology.
Source-Medindia