Familial aggregation in Behçet's disease: high frequency in siblings and parents of pediatric probands.

OBJECTIVE: To examine familial aggregation of Behçet's disease (BD) in pediatric compared with non-pediatric patients.

METHODS: A retrospective study was conducted to analyze data collected from 572 patients with BD in whom the diagnosis was made with criteria defined by the International Study Group for BD. The age of attaining criteria (the age at which the patient met the study group criteria) was evaluated for each patient. Recurrence risks were calculated for the pediatric group from information provided by 45 families.

RESULTS: Of the 505 patients from whom the age of attaining criteria could be ascertained, 106 showed definitive BD before the age of 16 years and were considered as pediatric patients with BD; the other 399 were classified as non-pediatric patients. Thirteen of the 106 pediatric patients (12.3%) and only 9 of the 399 non-pediatric patients (2.2%) had relatives affected by BD. This excess of familial cases in the pediatric group compared with the non-pediatric group was significant (P <.0001, chi2 analysis). Moreover, the mean age of attaining criteria in familial cases (17. 95 years [SD = 8.62]) was significantly lower than in sporadic cases (27.28 years [SD = 11]; P <.0001, Student t test). The recurrence risk among siblings and parents who met the International Study Group criteria was 0.1.

CONCLUSION: Our data support the hypothesis of a genetic component in the pathogenesis of BD, and we propose the inclusion of familial history in the definition of pediatric BD.