What Is the Life Expectancy for Fragile X Syndrome?

Individuals with fragile X syndrome (FXS) are more likely to experience cognitive impairment, physical abnormalities, and behavioral problems such as anxiety, aggressiveness, impatience, and repetitive behavior.

FXS does not affect everyone in the same way. Even members of the same family who have FXS do not exhibit the same symptoms.

Signs and symptoms of FXS include:

• Physical characteristics
  • Narrow face
  • Large head
  • Large and protruding ears
  • Prominent forehead and chin
  • Soft skin
  • Flat feet
  • Low muscle tone
  • Double-jointed fingers
  • Joint laxity (flexible or loose joints)
  • High arched palate
  • Large testicles (postpuberty)
• Behavioral characteristics
  • Sensory processing challenges (sensitive to certain fabrics or clothing, loud noises, crowds, food textures, and social interactions)
  • Hand-flapping and hand-biting
  • Poor eye contact
  • Attention deficit hyperactive disorder
  • Anxiety
  • Autism spectrum disorder
  • Increased risk of aggression
  • Sleep disorders
• Medical issues
  • Ear infections (often due to poor connective tissue)
  • Strabismus (crossed eyes)
  • Seizures
• Other issues
  • Delayed milestones in infancy
  • IQ is often in the range of 20 to 70, indicating mild-to-severe mental retardation
  • Toilet training problems
  • Failure to gain weight

FXS is a genetic condition. Although both sexes are affected by FXS, men are affected more frequently and may have more severe symptoms than women.

Mutations in the FMR1 gene cause fragile X syndrome (FXS). The FMR1 gene regulates the synthesis of a protein called FMRP, which stands for fragile X mental retardation protein. This protein promotes the formation of synapses (which are unique connections between nerve cells) and regulates the production of other proteins. The lack or shortage of this protein impairs nervous system function, resulting in the signs and symptoms of FXS.

FXS is inherited through the X chromosome. Women who are premutation carriers are more likely to have FXS offspring. If a woman's premutation carrier distributes the X chromosome containing the premutation to a child, the premutation may stay stable or grow, perhaps leading to a complete mutation.

Because the body may still produce FMRP, not everyone with a mutant FMR1 gene develops FXS. The severity of symptoms will be determined by how much protein the body can produce and the number of cells impacted.

Women may normally produce some FMRP as they have two X chromosomes. As a result, symptoms of FXS are often fewer in women than in men. FXS affects about 1 in every 4,000 men and 1 in every 8,000 women. 

Patients may seem normal at birth, but their development is usually delayed. Most patients with FXS experience mental disabilities ranging in severity from learning impairments to severe mental retardation.

FXS is the most common cause of inherited intellectual disability, and it can occur in any ethnic group.

Although there is no cure for fragile X syndrome (FXS), there are several interventions that can help those affected and their families. With proper education, therapy, and support, all affected individuals may improve. To handle the multiple difficulties encountered, a multidisciplinary approach is necessary.

The early years are crucial for encouraging optimal learning in children with the syndrome and early intervention can prevent many issues later. Family training to stimulate physical, verbal, and sensory training, as well as the development of a routine for the child, can all be provided as services.

Managing patients with FXS

• Genetic counseling
  • If a positive FXS test is detected, the family should be referred for genetic counseling. Family members at risk of carrying a complete mutation or permutation must undergo cascade testing.
  • Genetic counseling tries to educate families about the condition, its complications, and prognosis, assisting them in making educated future decisions and dealing with the emotional effect of the diagnosis. 
  • Counseling identifies individuals who may need to be informed about the diagnosis and the availability of testing.

Nonpharmacological management

• Family education
  • Family education and counseling are essential for facilitating parents' acceptance and comprehension of the child, as well as for encouraging patience and persistence with an uncooperative child.
  • A parent training program based on behavioral concepts can be recommended to help parents and families deal with issues of their child (such as sleep, behavior, and toilet education).
• Home environment
  • According to studies, modifications in the environment may affect behavior. In children with FXS, a better-quality family environment is related to less autistic behaviors, improved adaptive behavior, and higher IQ scores.
• Psychotherapy and counseling
  • Higher functional ability is noted in patients with FXS who have received psychotherapy and counseling. Psychotherapy or cognitive-behavioral therapies might target anxiety reduction through desensitization and other behavioral strategies, sexuality discussion, treatment, or depression management.

Pharmacological management

• Stimulants may be recommended to patients to deal with irritability and altered mood.
• Non-stimulants such as L-acetyl-carnitine may help treat attention deficit hyperactivity disorder symptoms in children with FXS.
• Antipsychotic drugs are regularly used to treat difficult behaviors such as aggressiveness and irritation. Risperidone is the most often administered antipsychotic medicine, and it is safe and effective against aggression in people with FXS.
• Fluoxetine and other selective serotonin reuptake inhibitors have been effective in patients with FXS who have social anxiety, autism, or selective mutism.
• Seizures with FXS are often well-controlled with medications such as carbamazepine and valproate. Recently, drugs such as lamotrigine, oxcarbazepine, zonisamide, and levetiracetam are effective anticonvulsants for individuals with difficult-to-control seizures, with the added benefit of having low cognitive side effects.

New treatments for FXS

• Metabotropic glutamate receptor (mGluR5) antagonists might be used to treat FXS. New mGluR5 antagonists are being developed and will be tested in patients with FXS in the future.
• Studies report that lithium can stabilize mood in patients with FXS while also providing functional benefits.
• According to research, patients with FXS have lower gamma-aminobutyric acid (GABA) inhibition in their brains. Aarbaclofen, a selective GABA-B receptor agonist, can reduce glutamate signaling in the brain. Aarbaclofen is now being examined in a clinical study of patients with FXS.

Managing associated medical conditions

• Because of the increased incidence of mitral valve prolapse and cardiomegaly, patients with FXS should have their cardiac functionality evaluated. 
• Individuals with FXS should be examined for conductive hearing loss, which can occur due to chronic ear infections.

In the last two decades, there have been substantial advances in FXS research. More efforts to introduce neonatal or infant screening for FXS may be made in the future. There is considerable optimism in the fragile X research community about new advances in targeted therapy for FXS. It is expected that future molecular therapeutics will be aimed at avoiding the onset of some FXS symptoms. In the future, we may see gene therapy interventions that entail inserting a functional copy of the FMR1 gene into brain cells, allowing the proper form of FMRP to be generated in the right place at the right time.