The inheritance of recurrent aphthous stomatitis. Observations on susceptibility.

In an effort to determine the prevalence of recurrent aphthous stomatitis (RAS), 1,303 children from 530 families were interviewed. While over-all disease prevalence in the children was 39.2 percent, there was a sharp difference in those children younger than 5 years (19.7 percent) and those 5 years of age and older (48.3 percent). Moreover, the prevalence of the disease in the children was significantly affected by whether RAS was present in none, one, or both of the parents. These observations suggest that disease susceptibility may be a complex interaction between host and environment.