The Xist Gene and Down Syndrome

New studies have shown that the Xist gene could be used to treat chromosome disorders such as Down Syndrome by silencing a chromosome. The method could help researchers to identify the cellular pathways behind the disorder's symptoms, and to design targeted treatments.

What is the Xist gene?

Figure 1- The expression of the Xist gene on one of the X
chromosomes leads to the recruitment of protein to that
chromosome that are required to inactivate the chromosome. 

Xist, which stands for X-inactive specific transcript, is an RNA gene on the X chromosome in placental mammals which affects the X inactivation process. According to NCBI Gene, X inactivation is an early developmental process in mammalian females that transcriptionally silences one of the pair of X chromosomes. As seen in Figure 1, this is because when the Xist gene is activated, it produces an RNA molecule that coats the surface of a chromosome like a blanket, which blocks other genes from being expressed (Beth Mole, nature.com).

Xist gene and Down Syndrome

Figure 2- The Xist gene can be used to
treat Down Syndrome as it
silences the extra copy of
chromosome 21

According to a study conducted by Jiang et al, the Xist gene can be used to silence one of the two X chromosomes carried by all females mammals, which is beneficial for chromosome disorders such as Down Syndrome as it can silence the extra copy of chromosome 21.











Bibliography:

Mole, Beth. Nature.com. Nature Publishing Group, n.d. Web. 12 May 2016.

http://www.nature.com/news/researchers-turn-off-down-s-syndrome-genes-1.13406

"XIST." Genetics Home Reference. N.p., n.d. Web. 12 May 2016.

https://ghr.nlm.nih.gov/gene/XIST#location