There are many myths associated with FXS that can contribute to a delayed or missed diagnosis. Here are some of the more common myths:
There is no value in making a diagnosis of FXS if there is no cure.
Although currently there is no cure for FXS, there are important supportive treatments that can be applied once the diagnosis is known. These include educational and therapeutic approaches tailored to individual strengths and weaknesses, screening for and treatment of medical issues, and behavioral treatment methods. Having a diagnosis also enables families to receive counseling for family planning, participate in clinical research if desired, and connect with support groups of other families affected by FXS.
All FXS patients can be recognized by their unusual physical features.
Individuals with FXS may have dysmorphic features like prominent ears, a long, narrow face, and large testes after puberty, but many children do not have any characteristic features. While some physical features may be seen in younger boys, most do not become evident until puberty, and girls do not have an unusual appearance.
Girls cannot have FXS, and boys with FXS are always severely affected.
Both girls and boys can have FXS. Symptoms are usually more severe in boys, but both boys and girls can exhibit symptoms ranging from normal functioning to severe intellectual disability.
FXS is diagnosed using a chromosome test or microarray.
FXS cannot be detected with a standard chromosome test or microarray. A specific test called the "FMR1 DNA Test for Fragile X (Fragile X DNA analysis)" must be ordered.
There has to be a family history of FXS for a child to have the condition.
Because the FXS mutation is an expanding mutation that can become bigger when passed on to the next generation, diagnosed individuals may lack a recognized family history of FXS. However, a family history of other fragile X-associated disorders, such as tremors and early menopause, can be an indication that a child with unexplained developmental delay, intellectual disability or autism has these features because of unrecognized FXS in the family.
Download the Fragile X Myth Busters handouts for pediatricians and families to share or post.
American Academy of Pediatrics