Fragile X Syndrome - Causes, Symptoms, Diagnosis and Prevention

Fragile X Syndrome: A Genetic Disorder

Dr.Manjeet Mehta profile Authored by Dr.Manjeet Mehta on 6 Jan 2015 - 14:19.

Fragile X Syndrome

Fragile X syndrome (FXS) or Martin-Bell syndrome is a genetic disorder that causes multiple developmental alterations including mental, behavioral, learning, cognitive and fertility (in females). FXS may cause seizures in 15 percent males and 5 percent females. The symptoms of FXS are usually picked up at later age. Being an X-linked condition, symptoms are expressed in males, with females being carriers.

Women with the premutated FMR1 gene pass the alteration to her child (both male and female) whereas; men with altered gene can pass FXS only to their daughter. One may have FXS even if both parents do not have it, this could be due to de novo alteration. Patients with FXS often need effective treatment interventions, care and support to lead their life productively, while facing these multiple challenges. 

FXS is caused due to altered FMR1 gene that is responsible for producing a protein (called fragile X mental retardation 1 protein) which regulates connection between nerves (synapses) and overall growth. Significantly altered gene creates the deficiency of FMR1 and so restricts the synthesis of protein regulating nerve connection thereby causing symptoms of FXS.

Fragile X syndrome is caused by expansion of the CGG trinucleotide repeat in the FMR1 gene. In these cases, the triplet CGG is abnormally repeated from 200 - 1,000 times. This causes the severe learning deficits or mental retardation and physical abnormalities in fragile X syndrome.

Only males express the typical features.The symptoms are usually noticed at puberty.

Common symptoms may include:

Developmental signs and symptoms:

  • Large forehead with prominent jaw line
  • Hand flapping
  • Hand biting
  • Inability to concentrate or learn
  • Delay in speech and language recognition
  • Lack of eye contact
  • Poor coordination
  • Anxiety

Physical signs:

  • Large forehead
  • Large prominent ears
  • Extremely soft skin
  • Long face
  • Large testicles

Not everybody who has FXS develops all the symptoms, occurrence and its severity may vary from person to person.

Complications: Possible complications of poorly managed FXS may vary with the type and severity of symptoms. These may include:

  • Increased risk of frequent infections
  • Seizure attacks
  • Increased risk of autism or similar disorders

In females, FMR1 gene exerts controlling functions on follicle recruitment and ovarian reserve, and on women's fecundity leading to Fragile X-Associated Primary Ovarian Insufficiency (FXPOI), also referred to as Premature Ovarian Failure (POF)

Diagnosis of FXS may involve a physical exam, assessment of family/ medical history and certain genetic tests.

Assessment of medical history: Examining family history

Physical examination: To assess any physical signs of FXS.

Genetic testing: A blood test to detect and identify an altered gene causing FXS.

Prenatal Testing: To detect the gene alteration in the developing fetus and/ or mother

As such there is no treatment specifically indicated in FXS, but certain treatments may be implemented to reduce the severity of the symptoms and to prevent further worsening and complications. However, various support groups, different therapies, self-help skills and trainings may help one to manage the condition effectively.

Drugs and medications: No drug is specifically indicated in FXS, but certain drugs can be used in conjugation with different therapies to obtain better results. However, benefits of medications cannot guarantee and they may also pose some severe health risks.

The Individualized Educational Plan (IEP): A special plan (IEP) will be designed by a team of specialists, teacher, care takers, psychologists, etc. to achieve learning goals based on his/ her capabilities.

Therapy Treatments: These may include:

  • Physical therapy: To strengthen the weaken muscles, bone and joints so as to improve and maintain good body posture.
  • Speech and language therapy: To improve overall communication by correcting the speech and language flaws like speech, pronunciation, coordination and so on.
  • Occupational therapy: To achieve daily living with optimum quality by adjusting tasks, needs and capabilities.
  • Behavioral therapy: To train the FXS patient to face the challenges positively and to teach them measures to avoid or respond to behavior related conditions.

Diet recommendations: Usually, healthy nutrition choices may not match with the likes and dislikes of FXS patients, especially in children. Try to make recipes of the following content that may attract children.

  • Foods rich in protein, vitamin and minerals
  • Olive oil
  • Eggs
  • Whole milk
  • Butter
  • Beans
  • Flaxseeds
  • Vegetables
  • Ketogenic diet
  • Avoid eating fatty foods, candy, chocolates, cold drinks and some more unhygienic and unhealthy foods.

Supplements: In order to fulfill the optimum requirement, may take the following supplements.

General tips for caretakers!

  • Identify their moods, likes-dislikes, the way of learning etc
  • Schedule a daily routine and follow the same
  • Use signs like picture, words, logos, etc to teach and develop various skills
  • Keep goals and work with specialists to achieve the same
  • Provide opportunities to explore their skills

It can be prevented by opting for genetic counseling if you have a family history of FXS and planning for pregnancy and genetic tests during pregnancy. 





*Disclaimer This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.