Snoring: all in the family.

If Mama and Papa snore loudly enough to raise the roof, chances are you do too, according to a study involving the families of patients with obstructive sleep apnea.

A report in the February American Review of Respiratory Disease presents evidence that this disorder, which is characterized by frequent pauses in breathing during sleep, may have a genetic cause.

Physician Susan Redline of the Cleveland Veterans Hospital and a team of colleagues in Ohio, Rhode Island and Massachusetts questioned the close relatives of 29 diagnosed sleep apnea patients. The researchers found that relatives of patients were nearly twice as likely as relatives of individuals without the disorder to report symptoms of sleep apnea--such as loud snoring, daytime sleepiness, and snorting or jerking during sleep. The association remained even when the researchers controlled for body weight and alcohol consumption, factors known to contribute to snoring and sleep apnea.

"These findings indicate that familial clustering of sleep apnea may be substantially more prevalent than has been suggested by the few published single-family studies," Redline's group writes. Sleep researchers currently estimate that between 1 and 4 percent of the U.S. population suffers from the disorder. Heritable traits that could cause sleep apnea include jaw abnormalities and longer-than-normal tongues or soft palates, Redline's group suggests.