The authors describe the familial incidence of Turner syndrome (TS) in a mother and her two daughters. In the mother, who was fertile, the 45X/46XX mosaic was detected. Both her daughters had caryotype 45X, but different phenotype. The older daughter had typical signs of TS (small stature, pterygium colli, streak gonads) and autoimmune thyroiditis. The younger daughter had adequate stature, lacked typical signs of TS, but suffered from oligomenorrhea. The authors draw attention to the risk of reproduction in women with the mosaic form.

        Key words: Turner syndrome, familial incidence, risk of reproduction in women with the mosaic form