What are CGG Repeats?

Fragile X-associated conditions are caused by a lengthening (expansion) in the FMR1 gene on the X chromosome.

The FMR1 gene is responsible for producing a protein called FMR1-Protein (FMRP), which is necessary for normal brain development and function.

At the beginning of the FMR1 gene there is a repeated sequence of chemical bases, known by the letters CGG. These are repeated a number of times.

Most people have less than 55 copies of this CGG repeat. Fragile X premutation carriers can have between 55 and 200 copies of the CGG repeat. People with the Fragile X full mutation (Fragile X syndrome) have over 200 copies of the CGG repeat.

DNA testing can determine how many copies of the CGG repeat a person will have.

diagram

Image credit: Women’s Health and the Fragile X Premutation, Sherman and Espinel, 2015, Emory University, Georgia, USA. 2015 https://issuu.com/fragilexaustralia/docs/final-pm-materials-12.13.15-short

Share:
Menu
Menu
Menu
Menu

We're fundraising for our Family Support service!

The spectacular Bridge to Beach paddle race raises funds to help us support, connect and advocate for families around Australia! You can make a difference for the Fragile X community by making a donation to our Bridge to Beach campaign today! Donations of $2.00 and over are tax deductible.

Fragile X Logo