Preliminary results of a genetic analysis: Stage I and Stage II-IV endometriosis may be 'entirely separate diseases'. (Gynecology).

SAN DIEGO -- Stage I endometriosis may have a different etiology than stage II-IV disease, according to preliminary results of a genetic analysis presented at the World Congress on Endometriosis.

"Perhaps we are talking about two entirely separate diseases within endometriosis," said Dr. Stephen H. Kennedy of the University of Oxford (England), one of the investigators.

The study included genotype data on 627 families, each of which had two sisters or other relatives with endometriosis. Although genetic linkage analysis identified no significant genetic link to endometriosis for the entire cohort, it did uncover the first suggestion of a significant linkage between one particular chromosome and endometriosis in the 399 families with stage II-IV disease.

The researchers also found possible linkages between endometriosis of any stage and four other chromosomes.

Preliminary analysis of questionnaires completed by 103 women with stage I endometriosis and 335 women with stage II-IV disease found tendencies toward earlier development of symptoms and later diagnosis in women with stage II-IV endometriosis.

In a separate presentation at the meeting, investigators from Iceland led by Dr. R.T. Geirsson found a fivefold increased risk of endometriosis in sisters of women with the disease in a nationwide genealogic study. They are embarking on a genomic scan of blood samples through linkage analysis to search for genetic roots of the disease.

"There is a very real possibility that the analysis of the genetic basis of endometriosis in this Icelandic population will lead to identification of the susceptibility gene," Dr. Kennedy said at the meeting, which was also sponsored by the World Endometriosis Society and the American Society for ...