Familial Behçet's disease of adult age: a report of 4 cases from a Behçet family.

A familial aggregation of Behçet's disease (BD) has long been noted. These studies have supported the direct role of HLA-B5 in the pathogenesis of BD. Despite the fact that familial clustering is characterized by genetic anticipation, accounting for the earlier disease onset in successive generations, we present two brothers and two cousins from the same family who were diagnosed when they were over twenty years old.We report these young adult patients to introduce the characteristics of familial aggregation of BD. In this article HLA-B*51 and Cw*16 positivities with adult onset were demonstrated.