Purpose: Familial occurrence has been reported in approximately 8% of Turki
sh patients with Behcet's disease. Our aim was to compare the clinical cour
se of ocular Behcet's disease among siblings. Methods: We retrospectively s
tudied five pairs of siblings with ocular involvement of Behcet's disease.
No other family member of these siblings had any symptom of Behcet's diseas
e. Results: The siblings comprised three sister-brother pairs, one sister-s
ister pair, and one brother-brother pair. There was a 5-10-year difference
between the age at onset of ocular disease among siblings. Three of the fiv
e pairs (two sister-brother, one brother-brother) had a dissimilar course o
f disease activity. Female siblings had an earlier age at onset and tended
to have a worse prognosis than their brothers. Conclusions: It is generally
acknowledged that male sex is associated with a worse prognosis. In this s
tudy, however, we observed that, among siblings with a dissimilar course, f
emale patients were more severely affected than male patients. Poor ocular
prognosis in a patient does not indicate aggressive treatment in his/her si
bling. We believe that each sibling should be managed on an individual basi
s.