Study of a kindred with thyroxine-binding globulin deficiency and oligomenorrhea

The finding of a low total thyroxine level in an oligomenorrheic woman uncovered a new family with thyroxine-binding globulin deficiency and oligomenorrhea. Thirteen of 17 family members had the deficiency of thyroxine-binding globulin, with heterozygous female subjects showing overlap of levels with normal subjects. Oligomenorrhea was frequently found but segregated separately from the thyroxine-binding globulin deficiency; of seven women with low levels, three had normal monthly menstrual cycles. Fertility was not impaired.