Medical Issues in Infancy

Most infants with fragile x syndrome are healthy and don’t require extensive medical intervention. However there are some common medical conditions which can occur more often in babies with Fragile X syndrome.

Congenital Abnormalities (Birth Defects)

  • Babies with FXS have an increased chance of some birth defects such cleft lip, cleft palate, clubfoot, congenital hip dislocation, and hernias, perhaps all related to loose connective tissue.
  • These are all common birth defects that happen in children without FXS as well, therefore babies with these conditions are not routinely tested for FXS unless there is some other indication, such as developemental delay or a family history of FXS.


  • Many babies with FXS have hypotonia or low muscle tone. Sometimes this is referred to as being “floppy” and sometimes it causes the baby to have difficulty in holding up their head or “head lag”.
  • Hypotonia can contribute to the developmental delay seen in babies and toddlers with FXS, because the low muscle tone effects their gross motor skills like sitting up, rolling over, etc.

GE Reflux

  • Although many babies with FXS do well in the newborn period, others have difficulty with feeding, vomiting and , gastroesophageal reflux (GER). This may be related to connective tissue abnormalities, low muscle tone (hypotonia), dysfunction of the gastroesophageal sphincter, or a hypersensitive gag reflex .
  • Some parents report that the vomiting in patients with GER often resolves with positioning upright after meals or with thicker baby food. Occasionally medication is needed to decrease reflux.
  • Occasionally a baby will be diagnosed with “failure to thrive” related to difficulties in sucking, GER, , or aversion to food textures If feeding difficulties are a problem, particularly sucking or intolerance of certain food textures, consultation with an occupational therapist and/or a speech and language therapist and subsequent work or oral desensitization, oral stimulation, and oral motor coordination can be helpful.

Otitis Media (Ear Infections) and Sinusitis (Sinus infections)

  • Beginning in the first year of life, frequent otitis media (middle ear infections) are a problem for many boys (and some girls) with FXS. In fact, often the speech and language delay seen in children with FXS is attributed to chronic ear infections, sometimes delaying the FXS diagnosis.
  • This problem requires treatment to avoid a hearing loss that may further compromise language development. If a conductive hearing loss persists after acute antibiotic treatment, sometimes “PE tubes” are recommended.
  • Recurrent sinusitis is also a common problem in FXS, and it may be related to the facial structure or the connective tissue problems that lead to recurrent ear infections.

Medical Issues in Children and Adolescents

Urinary tract infections

Some children, (more often boys), with FXS, may have an increased susceptibility to urinary tract infections and reflux (the backing up of urine into the urethra and bladder). The pediatrician may suspect this if the child has a fever of unknown origin with no other explanation, and thus a urine sample will be obtained.


Approximately 20% of males and a smaller percentage of females with FXS have seizures (epilepsy). If your physician suspects your child is having seizures often an EEG is performed. If seizures are confirmed, seizure medication is usually prescribed.

Opthalmology (Eye Disorders)

Children with FXS have an increased susceptibility for vision and eye disorders, which are common in childhood.

These include:

  • Strabismus: or “lazy eye” where the eye appear “crossed” or drifting to the middle. This is often due to low muscle tone in the eye, a symptom of the hypotonia present in many babies or children with FXS.
  • Ptosis: the drooping of the eyelid, again often related to low muscle tone.
  • Nystagmus: the shaking of the iris in a back and forth motion, often subtle far sightedness and near sightedness (myopia, or hyperopia).

It is recommended that all children with FXS be referred to an ophthalmologist if the pediatrician suspects any of these common eye or vision conditions.

Connective Tissue Issues

Connective tissue is the tissue that holds together the body such as skin, muscles, tendons, cartilidge, and ligaments, bone and blood vessels. Many individuals with FXS have differences in their connective tissue. Some of these connective tissue problems include:

  • Scoliosis: curvature of the spine, usually not severe.
  • Flat feet: also called pes planus.
  • Hernias: inguinal hernias.
  • Cardiac murmur: often a “functional” or “ innocent” murmur, sometimes indicative of mitral valve prolapse (MVP). Occasionally an evaluation by a cardiologist is warranted to confirm the MVP. If the MVP is confirmed the cardiologist may recommend antibiotics prior to dental procedures or surgery.
  • Hyperflexible joints: particularly of the wrists, fingers and elbows, and soft skin.
  • Macroorchidism (enlarged testicles): Testicular volume normally increases during the early stages of puberty, but in boys with FXS this increase is usually quite dramatic, leading to macroorchidism (enlarged testicles). These changes are typical for FXS, and they do not require intervention. Some boys with FXS develop large testicles prior to the onset of puberty.