A team from Sweden and the USA investigated the genetic influence in the development of gastroesophageal reflux disease (GERD).
Concordance for reflux in monozygotic (MZ) and dizygotic (DZ) twins was compared.
All twins aged 55 years and older in the nationwide Swedish Twin Registry were invited to participate in the study.
Data were collected by computer-assisted telephone interviews.
Symptomatic heartburn or acid regurgitation, occurring at least weekly, defined reflux disease.
A total of 2178 monozygotic, 3219 same-sex dizygotic, and 3014 unlike-sex dizygotic twin pairs provided information.
| Heritability accounted for 31% of the liability to GERD.
| Gastroenterology |
The researchers found that, overall, 15.3% of the twins had reflux.
In men, the intraclass correlation for reflux was 0.29 for monozygotic and 0.13 for dizygotic pairs.
In women, the correlation was 0.33 for monozygotic and 0.14 for dizygotic pairs.
The team found that, for unlike-sex dizygotic pairs, the correlation was 0.06.
Inherited obesity or alcohol use did not cause concordance for reflux. However, inherited smoking may be a minor factor.
Author Alan J. Cameron, of the Mayo Clinic, Rochester, Minnesota, USA, said on behalf of his colleagues, "The increased concordance for reflux in monozygotic pairs, compared with dizygotic pairs, indicates genetic rather than shared environmental effects.
"Heritability accounted for 31% of the liability to reflux disease in this population," he concluded.