['To investigate a possible association between the carrier frequency of the N314D mutation in the galactose-1-phosphate uridyl transferase (GALT) gene and endometriosis and linkage to the short arm of chromosome 9, where the GALT gene resides.', 'Association and linkage study.', 'Population material collected for case and family studies in endometriosis.', 'Women diagnosed with endometriosis by laparotomy or laparoscopy.', 'Association with the GALT gene investigated by genotyping 85 affected women and 213 unrelated control women and a scan for linkage to chromosome 9 in 205 women from 64 families with endometriosis.', 'Multipoint parametric lod scores and frequency of alleles.', 'There was no significant difference in allele frequency for the N314D polymorphism in patients compared with control subjects. No evidence for linkage was found to chromosome 9p, where the GALT gene resides.'] Is endometriosis associated with or linked to the GALT gene?