Treacher Collins Syndrome

Treacher Collins syndrome (TCS), also called mandibulofacial dysostosis, is a rare congenital (present from birth) disorder characterized by craniofacial deformities, such as underdeveloped cheekbones and jawbones. Children with this condition have very small or partially absent cheekbones and notches in or stretching of the lower eyelids. The ears are frequently abnormal and part of the outer ear is usually absent. The lower jaw is also small. Hearing loss is also associated with this syndrome.

Treacher Collins syndrome occurs in about 1 of 10,000 births. Adults with Treacher Collins syndrome have a 50% chance of passing the condition to their children. When a parent with Treacher Collins syndrome passes on the genes, the children may be affected in varying degrees. The degree may be the same as the parent, milder, or more severe. 

Patients can be seen by Texas Children's experts in Plastic Surgery and Craniofacial and Craniosynostosis Clinic.

Causes & Risk Factors

Treacher Collins syndrome is caused by mutations in various genes. There are 2 ways in which this condition may be passed:

One way is as a new mutation. This means that both parents pass on normal genes to their child. However, sometimes very early in development a change in one of the genes leads to this mutation. At the present, there is no evidence that the mother’s actions or activities during her pregnancy contribute to this condition.

The second way that Treacher Collins syndrome develops is by inheriting it from one of the parents. It should be noted that sometimes one of the parents may have such a mild form of the condition that it goes undetected. It is not until a child is born with the syndrome that it is realized that the mother or father also has the condition.  

Symptoms & Types

Several problems are common in Treacher Collins syndrome. A child does not necessarily have all of these problems, but most affected individuals have underdeveloped facial bones, particularly the cheekbones, and a very small jaw and chin (micrognathia). Other common difficulties involve:

  • The external ear(s) are abnormal or almost completely missing
  • Hearing loss
  • Defect in the lower eyelid, (drooping), which makes them appear to be sad
  • Scalp hair that reaches to the cheeks
  • Cleft palate (opening in the roof of the mouth)

A very small percentage of children will have some problem with their hands. One of the more common problems involves the thumbs. The thumbs are either absent or abnormally small. A bilateral absence (absence of both thumbs) may mean that the child has a syndrome called Nager syndrome.

In severe cases, underdevelopment of the facial bones may restrict an affected infant's airway, causing potentially life-threatening respiratory problems. A small underdeveloped jaw may cause the tongue to be positioned farther back toward the throat, resulting in a smaller airway. 

Diagnosis & Tests

Sometimes Treacher Collins syndrome is diagnosed before a baby is born because the abnormal facial features may be visible during an ultrasound. At birth, your child's doctor can usually make the diagnosis by assessing the signs and symptoms of your baby, and then genetic tests can help identify and confirm any gene changes linked to this condition.

Physical examination of the infant may reveal a variety of problems, including:

  • Abnormal eye shape
  • Flat cheekbones
  • Clefts in the face
  • Small jaw
  • Low-set ears
  • Abnormally formed ears
  • Abnormal ear canal
  • Hearing loss
  • Defects in the eye (drooping that extends into the lower lid)
  • Decreased eyelashes on the lower eyelid

It is important to have the child’s hearing tested at an early age. Most children have a 40% hearing loss in each ear. X-ray or CT scan may be used in questionable circumstances. A CT scan is an X-ray procedure that takes a computer-enhanced cross-sectional view of the body. 

Treatment & Care

No single specialist can manage TCS and its associated problems. Proper treatment usually involves a team of doctors who specialize in many areas. A craniofacial or pediatric plastic surgeon along with an ear, nose and throat doctor are very important, because children with this condition sometimes need a series of operations that must be coordinated. Hearing loss should be treated as early as possible to ensure better performance in school.

Depending on the severity of the disorder, your child may require some or all of the following treatments:

  • surgery to re-shape the cheekbones
  • surgery to repair nose and eyelids
  • surgical reconstruction of the ears
  • surgery to improve feeding and/or breathing
  • hearing tests with an audiologist
  • special hearing aids
  • speech therapy
  • orthodontics, to straighten teeth
  • surgery to lengthen the lower jaw
  • jaw surgery to align the upper and lower jaw
  • surgery to fill in the cheeks and soft tissue of the face

Living & Managing

Genetic counseling is recommended if you have a family history of this syndrome and wish to become pregnant.

Pay careful attention to any feeding, breathing, hearing, visual, or any other problems your child may have will help ensure better performance in school.

A pediatric psychologist is highly recommended. They perform two important functions:

  • Monitor the child’s development to determine a need for intervention in helping your child reach his potential.
  • Help your child to cope with the stress and pressures arising from his medical condition.

The psychologist can often provide parents with suggestions for dealing with interpersonal relationships. This is especially helpful with handling problems with children at school.

In general, children with this syndrome typically grow to become normally functioning adults of normal intelligence. 

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