- Prenatal diagnosis of a small supernumerary, XIST-negative, mosaic ring X chromosome identified by fluorescence in situ hybridization in an abnormal male fetus. Le Caignec, C., Boceno, M., Joubert, M., Winer, N., Aubron, F., Fallet-Bianco, C., Rival, J.M. Prenat. Diagn. (2003)