1. Is it necessary to detect fragile X chromosome?

Fragile X syndrome leads to mental retardation (Martin bell syndrome). Fragile X syndrome is caused by mutations in the formation of X chromosome in human body. A segment of DNA on the X chromosome can sometimes change due to genetic relationships. One is complete change, the other is DNA hypermethylation. If the degree of these two changes is small, the patient can have no special symptoms or only slight symptoms in clinical performance. On the contrary, if the degree of these two changes is large, the following symptoms of fragile X syndrome may appear.