How to check for fragile X syndrome

Update Date: 2025-07-15 Source: Network

summary

Intelligence is more important in our life. Some diseases will seriously affect the development of human intelligence, such as fragile X syndrome. We can only talk about the prevention and treatment of fragile X syndrome as soon as possible.

How to check for fragile X syndrome

First, because of the genetic instability of the (CGG) n trinucleotide repeat sequence in the 5 'untranslated region of the fragile X mental retardation gene (FMR1), the (CGG) n is about 8-50 copies in normal individuals, while it increases to 52-200 copies in normal male and female carriers, and the adjacent CpG island is not methylated, which is called premutation.

Second, the pre mutation had no or only mild symptoms. The CGG region of female carriers is unstable, and the copy number increases progressively (i.e. dynamic mutation) in the process of transmission to offspring, so that in male patients and women with high expression of fragile sites, the number of CGG repeats reaches 200-1000 copies, and the adjacent CpG islands are also methylated, which is called full mutation. Almost all patients did not express or only had low expression of FMR1 mRNA, resulting in clinical symptoms. This is one of the typical diseases of dynamic mutation.

Third, the diagnosis can be made according to the typical clinical symptoms. The diagnosis of fragile X syndrome can be made by karyotype analysis. The detection rate of fragile X chromosome was affected by the composition of medium and time. Removal of folic acid from the medium or addition of mutagens were beneficial to the detection. Detection of FMRP protein by specific antibody of FMR1 gene encoding protein is also a common method for the diagnosis of fragile X syndrome.

matters needing attention

Due to the continuous progress of medical technology, there are many diseases that can be treated well and do little harm to human body. If the fragile X syndrome is not treated properly, it may cause some complications. Now, it is generally diagnosed by chromosome analysis in medicine.