Fainting may run in families while triggers may not

April 15, 2013

New research suggests that fainting may be genetic and, in some families, only one gene may be responsible. However, a predisposition to certain triggers, such as emotional distress or the sight of blood, may not be inherited. The study is published in the April 16, 2013, print issue of Neurology. Fainting, also called vasovagal syncope, is a brief loss of consciousness when your body reacts to certain triggers. It affects at least one out of four people.

"Our study strengthens the evidence that fainting may be commonly genetic," 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. "Our hope is to uncover the mystery of this phenomenon so that we can recognize the risk or reduce the occurrence in people as fainting may be a safety issue."

Researchers interviewed 44 families with a history of fainting and reviewed their medical records. Of those, six families had a large number of affected people, suggesting that a single gene was running through the family. The first family consisted of 30 affected people over three generations with an average fainting onset of eight to nine years. The other families were made up of four to 14 affected family members. Affected family members reported typical triggers, such as the sight of blood, injury, , prolonged standing, pain and frightening thoughts. However, the triggers varied greatly within the families.

Genotyping of the largest family showed significant linkage to a specific region on , known as 15q26. Linkage to this region was excluded in two medium-sized families but not in the two smaller families.

Explore further: Family tree may clarify death risk for inherited heart rhythm disorders

Related Stories

Pacemaker prevents fainting among select patient population

March 26, 2012

A select number of patients who suffer from neurally mediated synope (NMS) – a disorder in which the brain fails to regulate heart rate and blood pressure – may be good candidates to receive a dual-chamber pacemaker ...

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 ...

Fainting in healthy people may be first sign of heart trouble

December 12, 2012

(HealthDay)—Fainting isn't fun. For those who have ever suddenly and briefly lost consciousness, it's a disconcerting situation that typically triggers a thorough medical workup. Unfortunately, it's often tough for physicians ...

Recommended for you

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...


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.