XIST LPU018 - Detail

One X chromosome is inactivated (Xi) in each cell of a female in order to achieve transcriptional balance. An X linked inactivation centre (Xic) is responsible for the initiation of X inactivation. The exact size of the Xic is unclear but it includes the XIST gene (X-inactivation Locus) at Xq13.2. Upregulation of XIST to high levels occurs on the chosen inactive (Xi) chromosome and repression of XIST on the active (Xa) one¹. Very small ring r(X) chromosomes that do not include XIST have been described with a more severe phenotype in syndromes such as Turner Syndrome ^{2, 3}.

Reference:/Bibliographie/Literatur/Bibliografia

1. Boumil R.M. and Lee J.T., et al (2001) Hum Mol Genet 10 (20): 2225-2232
2. Le Caignec C., et al (2003) Prenat Diagn 23 (2): 143-145
3. Bouayed Abdelmoula N., (2004) Ann Genet 47 (3): 305-313