February 28, 2014

Brett Smith for redOrbit.com Your Universe Online

New research from a team of American researchers has found a genetic mechanism that shuts off the gene associated with fragile X syndrome which causes developmental disorders such as mental retardation and autism.

According to the teams report in the journal Science, they were successfully able to a test drug that blocks this blocking mechanism.

While it has been known that the syndrome is driven by the excessive repetition of the certain portion of the genetic code, geneticists havent known why these repetitions set off the disease.

To reach their findings, the team used donated stem cells from human embryos that tested positive for fragile X syndrome.

These stem cells were critical to the success of this research, because they alone allowed us to mimic what happens to the fragile X gene during embryonic development, said study author Dilek Colak, a postdoctoral scientist at Cornell Universitys Weill Cornell Medical College.

The stem cells were stimulated to become brain cells and at an early point in their development about 50 days protein-producing messenger RNA (mRNA) in the cells was seen sticking to the syndrome-causing DNA. This joining made the gene inactive and not able to produce an important protein that facilitates signaling between brain cells.

Until 11 weeks of gestation, the fragile X syndrome gene is active it produces its messenger RNA and protein normally. Then, all of a sudden it turns off, and stays off for the rest of the patients lifetime, causing fragile X syndrome. But scientists have not understood why this gene gets shut off, said study author Samie Jaffrey, a professor of pharmacology at Weill Cornell Medical College. We discovered that the messenger RNA can jam up one strand of the genes DNA, shutting down the gene which was not known before.

This is new biology an interaction between the RNA and the DNA of the fragile X syndrome gene causes disease, he added. We are coming to understand that RNAs are powerful molecules that can regulate gene expression, but this mechanism is completely novel and very exciting.

Read more:
Interaction Between RNA And DNA Of Fragile X Gene Causes The Disease

Comments are closed.