Familial inheritance of endometriosis in a British population. A case control study

Abstract

The incidence of endometriosis in the tirst degree relatives of 64 women with a visual diagnosis of endometriosis, the index group, was compared with 128 case controls with no known endometriosis. Data was collected by interview and attempts made to independently verify the diagnosis of the relatives. The number with a first degree relative with endometriosis was six (94 per cent) in the index group which was higher (P < 0-05, Fisher's exact test) than the two women (1-6 per cent) in the control group. The 95 per cent coincidence limits for the difference in percentages were 0-36 to 15-3 per cent. Within the total population of tirst degree relatives the percentage with endometriosis was also higher (P < 0-05) in the index group (5-5 per cent) compared with the control group (0-7 per cent); coincidence limits for difference 0-6 to 8-5 per cent. This verifies previous reports of a higher incidence of endometriosis in the first degree relatives of suffers of endometriosis, suggesting there may be a famililar tendency.