Answers to questions families often have about caring for their child with fragile X syndrome

Fragile X syndrome is a single gene mutation of fragile X messenger ribonucleoprotein 1 (FMR1) on the X chromosome that can be inherited. This genetic difference can cause a spectrum of intellectual disability, autism, and behavioral challenges. While there is not yet a cure, therapies, interventions, and medication can help improve symptoms and behaviors.

The gene mutation that causes fragile x syndrome is found on the X chromosome. Males are usually more affected than females since they have only one X chromosome. Features may include intellectual disabilities, ranging from mild learning disabilities to more severe impairments, ADHD, anxiety, unstable mood, autistic behaviors, sensory integration problems such as hypersensitivity to loud noises or bright lights, speech delay (with expressive language more severely affected than receptive language), and seizures. Physical features are usually hard to recognize in babies and young children but sometimes become more apparent with age. They are a long face, large ears, flat feet, hyperextensible joints, low muscle tone, and in adult men, large testes.

Testing for fragile X syndrome is done by a simple and reliable DNA blood test. This test is widely available, so talk with your doctor. Your pediatrician can order it, but they may refer you to a geneticist or Fragile X specialist for interpretation. Other diagnoses that may be mistaken for Fragile X include Fragile XE syndrome, Klinefelter syndrome, Sotos syndrome, and Prader-Willi syndrome.

Prognosis is a spectrum. People can be mild to severely affected. Things that can help improve outcomes are 1) physical, occupational, speech, and behavioral therapies; 2) medication management; and 3) intrinsic factors. Life expectancy for individuals with fragile X is normal.

There is a 50% chance that a child will inherit the affected X chromosome. This should be discussed with your doctor, as the risks can be better estimated with more information about the mother's genetics. Prenatal testing for fragile X is available.

As of now, there is no cure for fragile X, although appropriate education and medications can help each child reach their potential. Most boys and many girls will continue to show FXS symptoms throughout their lives.

A child can have fragile X syndrome and not have autism. About 40% of males and less than 40% of females with fragile X syndrome exhibit significant autistic behaviors. Autistic behaviors include poor eye contact, hand-flapping, self-injurious behavior, and poor sensory skills. See Autism Spectrum Disorder (FAQ).

Extended family members of individuals with fragile X syndrome may have related disorders, including social problems, learning disabilities, premature ovarian failure, and fragile X-associated tremor/ataxia syndrome. They sometimes receive screening for proactive care of problems that may arise and to give genetic counselors more information to better counsel a family about reproductive risk.