The genomic colocalization of OSR1 and NCOA1 together with the finding of uterine estrogen insensitivity in the affected sisters is coincident with a relationship between the OSR1 mutant and impaired endometrial biology in the context of sex steroid dysregulation in the FRT, particularly endometrial estrogen insensitivity and resultant uterine factor infertility. This evidence concerns the gene OSR1 and Infertility.