Familial Behçet's disease.

OBJECTIVES: To highlight the frequency, clinical features and histocompatibility antigen types of the familial form of Behcet's disease. METHODS: Twenty-seven cases with familial Behcet's disease in 12 families were evaluated according to clinical features, sites of involvement, HLA-A and HLA-B typing. A review of the literature is presented. RESULTS: The frequency of familial form of Behcet's disease was found to be 8.7% among 137 patients studied. Vascular involvement was 7.4% (2/27) in the familial group while it was 28.8% (36/125) in patients without the familial form of the disease (p < 0.01). HLA-B51(5) and HLA-A2 were positive in 68% and 75% in 16 familial cases studied, respectively. CONCLUSIONS: Familial Behcet's disease, which constitutes a small group of patients with Behcet's disease, may represent a clinically heterogeneous subtype of this entity. Although lower frequency of vascular complications was observed in this study, it is not possible to indicate the precise frequency of vascular and ocular complications of the familial form of Behcet's disease. The frequencies of HLA-A2 and HLA-B51(5) positivity are higher than the previously reported non-Behcet's controls from Turkey.