Fragile X syndrome is a genetic disorder that causes a spectrum of complications including learning disabilities and cognitive impairment. Males tend to be more affected than females. This is because the syndrome is caused by a mutation of a gene located on the X chromosome. As females have two X chromosomes, if they inherit one chromosome carrying the mutation, they always have another with the normal gene. However, in males, since they have only one X chromosome, if it carries the mutation, the male will suffer from Fragile X syndrome.
Approximately one in 8,000 females and one in 4,000 males are affected by this disease; whereas 1 in 600 females are healthy carriers. Twenty percent of healthy female carriers of this mutation will develop primary ovarian failure before the age of 40. In addition, the ovarian reserve in these women is lower.
When there is a family history of Fragile X syndrome, genetic counseling should be sought. A Fragile X study should also be performed in those patients who present an abnormally low ovarian reserve for their age.
Once the syndrome has been diagnosed and in order to avoid having an affected child, treatment should be by in vitro fertilization with preimplantation genetic diagnosis (genetically analyzing the embryos before transferring them) in cases of good ovarian reserve or IVF with donor eggs if the woman has low ovarian reserve and/or early ovarian failure.