Description of Fragile X syndrome

The basic description of Fragile X syndrome is that it is a genetic problem located in the chromosomal band Xq27.3 to be exact.



Normally, individuals have between 6 and 52 repeats of CGG per FMR1 allele. If a female carrier has an unstable repeat region which may lead to further expansion in the meiosis of germ cells, she may pass on more than 200 copies of full mutations alleles to her children. Children with full alleles have a greater risk of mental retardation.

The best way to give a description of Fragile X syndrome to friends and relatives is to explain that it is caused by a break or a weakness in the long arm of the X chromosome. Males have an X and Y chromosomes while females have two X’s.

Fragile X occurs in 1 of 1,100 males and in 1 of 2,500 females. Moms who are carriers have a 50% chance of passing on the Fragile X syndrome to their children. Dads who are carriers can only pass it on to their daughters.

The description of Fragile X was first made in 1969 and was named in the late 70’s. With the creation of the World Wide Web, Fragile X syndrome has become more visible to the general public. Although research continues, at this point there is no known cure for Fragile X syndrome.

It is important to note that Fragile X, like Autism Spectrum Disorder, has a wide range of levels that affect the individuals. Early intervention is important and treatments include: speech, physical and occupational therapies.

If you have any concerns, please ask your doctor for a description of Fragile X and if they feel that a DNA blood test will be necessary. Early intervention is crucial, if you do not feel comfortable with the answers that you have received then please do seek a second opinion.