Purpose: The study aimed to identify families with endometriosis and to document disease severity within the families and the clinical characteristics of the affected women.
Results: Two hundred and thirty women with surgically confirmed endometriosis in 100 families were identified. The families consisted of 19 mother-daughter pairs, 1 set of cousins and 56 sister pairs. There were 5 families with 3 affected sisters, 1 family with 5 affected sisters, and 18 families with > or = 3 affected members in more than one generation. The mean age at the onset of symptoms and the mean age at surgical diagnosis was 22.1 +/- 8.8 SD (range 10-46) and 31.8 +/- 7.9 SD (range 15-56) years respectively. Seventy-nine women (34.3%) had revised AFS Stage I-II disease, and 151 (65.7%) had revised AFS Stage III-IV disease.
Conclusion: The study confirms a familial tendency for endometriosis and supports the hypothesis that endometriosis has a genetic basis.