Ring chromosome 21 in the mother and 21/21 translocation in the fetus: karyotype: 45,XX,-21,-21,+t(21;21)(p11;q11).

In 1984 we reported a ring chromosome 21 in a normal woman with recurrent fetal wastage (Kleczkowska and Fryns, 1984). A 46,XY normal fetal karyotype was found after prenatal diagnosis at 14 1/2 weeks in a third pregnancy of this woman. In the present paper we report the prenatal diagnosis of a 21/21 translocation in a female fetus from her fourth pregnancy.