- Deficient transcription of XIST from tiny ring X chromosomes in females with severe phenotypes. Migeon, B.R., Luo, S., Stasiowski, B.A., Jani, M., Axelman, J., Van Dyke, D.L., Weiss, L., Jacobs, P.A., Yang-Feng, T.L., Wiley, J.E. Proc. Natl. Acad. Sci. U.S.A. (1993)