What is Treacher Collins Syndrome?
Treacher Collins syndrome (TCS) is a condition where some of the bones and tissues in the face aren’t fully developed. It is a rare genetic condition, and can range from relatively mild to very severe. The jaw, ears, eyelids and cheekbones can be affected.
In more severe cases, a child will have a very small jaw (mandible). Often times that can lead to breathing problems and can result in the need for a tracheostomy. Ear abnormalities can also occur, with small or malformed ears that cause severe conductive hearing loss. Eyelid abnormalities can include the inability to completely close the eyes.
This syndrome occurs in roughly 1 in 20,000 births.
TCS has symptoms similar to other disorders that are part of a larger group, called mandibulofacial dysostoses. Another large group, called acrofacial dysostoses, shares similar symptoms in addition to limb defects. Disorders that fall in this group include Nager syndrome, Miller syndrome, as well as others. The treatment approach is similar for all of these disorders.
Causes of TCS
Treacher Collins syndrome is caused by a gene mutation. Most commonly, a mutation is found in the gene TC0F1. The other genes known to cause the syndrome are POLR1C and POLR1D. About 40% of births are hereditary (passed from parent to child) while the other 60% are new mutations.
At Cincinnati Children’s, our Division of Human Genetics plays an important role in the treatment and management of this condition. For families with known or suspected Treacher Collins syndrome, we offer a comprehensive genetics evaluation where we discuss genetic issues such as risk of recurrence and reproductive options. Prenatal evaluation through the Cincinnati Fetal Care Center is sometimes an option as well.
Signs and Symptoms of TCS
Because the severity of Treacher Collins syndrome can vary widely, the symptoms also vary. A patient who is mildly affected might have minor features of eye changes, such as the eyes slanting downward a bit. Hearing may be normal, or the child might have mild conductive hearing loss. A child with a more severe case will have more pronounced abnormalities.
Individuals may have any of the following characteristics:
- Very small jaw and chin (micrognathia)
- A notch in the lower eyelids (eyelid coloboma)
- Absent, small or unusually formed ears
- Hearing loss
- Underdeveloped or absent bones of the midface (zygoma and orbit)
- Downslanting eyes
- Malformed lower eyelids with sparse eyelashes
- Flattened or incomplete cheekbones
- Large nose
- Blocked, narrowed or partially blocked nasal passageways (choanal atresia, choanal stenosis or deviated septum)
- Large or malformed outer ears (microtia)
- Small or missing ear canals (atresia)
- Middle ear tiny bone (ossicle) malformations
- Opening in the roof of the mouth (cleft palate)
These characteristics may cause issues with eating, breathing, swallowing, hearing and more.
It’s possible that a parent of a child with severe Treacher Collins syndrome is affected but doesn’t know it because the parent’s case is so mild.
Diagnosis of TCS
Most cases of Treacher Collins syndrome are diagnosed soon after birth or within the first year of life. However, it can be diagnosed later in life, especially if it’s a very mild case.
Doctors familiar with the condition often make the diagnosis based on the appearance of the face. Sometimes a special X-ray, called a 3D CT scan, is used to view the facial features in further detail. The diagnosis is confirmed with genetic testing.
Treatment of TCS
Children with Treacher Collins syndrome often need care from variety of specialists, including:
- Human Genetics
- Pulmonary Medicine
- Plastic Surgery
- Otolaryngology / ENT
- Neonatology
- Speech Pathology
- Feeding Team
- Upper Airway Center
- Audiology
A typical course of care involves an age-based approach:
- Infants: The main focus is to ensure the baby has a stable airway. If the size of the lower jaw needs to be increased (mandibular distraction), that is often done at this time. Feeding is also a main concern early on. A tracheostomy might be performed during infancy. Hearing can be addressed at this time with bone-anchored hearing aids if necessary.
- Childhood: As the child grows and starts the school-age years, physical appearance is often addressed. Children ages 6-8 might have another distraction surgery if sleep apnea is still a problem. Other surgeries at this time can include repairing the eyelids and reconstructing the ear.
- Adolescence: Teens sometimes undergo additional surgeries to address further physical characteristics. Procedures depend on each child and how their facial bones and tissues have grown throughout childhood. They might have upper or lower jaw surgery, and/or bone grafting and rhinoplasty if needed. Orthodontics is often addressed at this time as well.
Long-Term Outlook
Today, technologies such as bone-anchored hearing aids / Baha, and surgeries such as those to expand the jaw, allow many children with TCS to lead normal lives. The long-term outlook depends on how severe the syndrome is. A mild case may require little intervention, while other patients may have severe breathing problems and require a tracheostomy all their life. The syndrome does not affect children’s ability to learn or be active.
Patients will likely continue to have follow-up appointments to monitor their growth and to watch for any related issues that may come up.
Associated Complications
Some complications related to Treacher Collins syndrome are:
- Obstructive sleep apnea (OSA)
- Cleft palate
- Feeding issues
