Aim: To estimate the probability that the parents of patients with Kawasaki disease also had a history of the same disease.
Methods: Self-reported parents' histories of Kawasaki disease were collected from data of the 16th nationwide survey of the disease conducted in Japan from January 1999 to December 2000. The incidence of Kawasaki disease was calculated by using data reported in all 16 nationwide surveys and live births in the Japanese vital statistics. The expected number of parents with a history of Kawasaki disease in the general population, which was calculated by using the assumed number of parents in the vital statistics and the incidence of this disease, was compared with the observed number.
Results: Among 14,163 parent pairs of patients with Kawasaki disease, 33 parents (25 mothers and 8 fathers) had a history of the disease. The number of parents expected to have a history of Kawasaki disease was 16.1 (8.4 mothers and 7.7 fathers). From a Poisson distribution, the probability of the observed number was less than 0.001 among parents or mothers. The prevalence of a recurrence of Kawasaki disease and incidences involving siblings of patients whose parents had a history of the disease were five or six times higher than those of all patients who were reported in the 16th survey.
Conclusion: When compared with parents in the general population, the probability of a history of Kawasaki disease was significantly higher in those parents whose children suffered from the same disease. This suggests that, epidemiologically, a genetic predisposition to Kawasaki disease may be implicated in its occurrence.