MUC 1: a genetic susceptibility to infertility?

In man and some animals regulation of embryo Implantation by endometrial ex pression of the highly polymorphic MUC 1 mucin has been suggested. We asses sed the polymorphism of MUC 1 in women known to be fertile and those with i nfertility due to suspected failure of embryo implantation. The median of t he lower allele size in the infertile group was only 2.5 kb compared with 3 .4 kb in the fertile group (p=0.0029, difference 0.9, [95% CI 0.1-1.3]). Wo man with unexplained Infertility might have a genetic susceptibility to fai lure of embryo implantation due to small MUC 1 allele size.