Familial aggregation of Behcet's disease in Turkey

Objective-Familial aggregation of Behcet's disease has been reported previo usly. The current study aimed at investigating the sibling recurrence risk ratio (lambda s) for Behcet's disease, which is of value in the estimation of the magnitude of genetic factors in the pathogenesis of Behcet's disease . Methods-170 consecutive unrelated index cases (98 male, 72 female) were i nterviewed with a detailed questionnaire to ascertain their family trees an d the manifestations of Behcet's disease in their relatives, Subsequently, the immediately older sibling, or if an older sibling was not available, th e immediately younger sibling, was selected as the second sibling for the e valuation. These siblings were contacted by telephone, and all subjects wit h recurrent oral ulcers were invited for examination. Results-31 of the 170 index cases had 51 relatives fulfilling the Internati onal Study Group criteria, Among 166 second siblings, seven had Behcet's di sease (six male, one female) and 22 siblings (eight male, 14 female) with r ecurrent oral ulcers were identified. Sibling recurrence rate-defined as th e ratio of the risk of being affected among the siblings of patients and th e risk of being affected in the general population- was found to be 4.2%. w hich gives a lambda s value for Behcet's disease of between 11.4 and 52.5 i n Turkey. Conclusions-A high lambda s value supports a strong genetic background for Behcet's disease which will be helpful in designing genetic Linkage studies .