Treacher Collins syndrome is a rare genetic condition affecting the growth of the cheek bones, the lower jaw and the ears. The syndrome is also notable for very characteristic down-slanting of the eyes. Studies have shown that Treacher Collins syndrome occurs in approximately 1 in 10,000 births.
Cause of Treacher Collins syndrome
Treacher Collins syndrome is caused by a genetic mutation of a gene called the TCOF1 (or Treacle) gene, located on chromosome 5. Most cases are the result of a new mutation which occurs by chance. It is generally not the result of anything that either parent did or failed to do. However, individuals with Treacher Collins syndrome may pass the condition on to their children. The gene is passed in an autosomal dominant fashion, meaning that a parent with Treacher Collins syndrome has a 50% chance of passing that gene on to their child.
Every child with Treacher Collins syndrome is different. Which features children have and how severely affected they are will vary. The most common characteristic traits include:
- A narrow forehead
- Eyes that tilts downward (called an "antimongoloid" slant)
- Pulled down lower eyelids
- Absent eyelashes on the lower eyelids
- Thin skin overlying absent cheekbones (orbital clefts with absent zygomas)
- Absent ears (microtia), or malformed ears
- Cleft palate
- Small lower jaw
As a result of the abnormal growth of the facial bones, some children with Treacher Collins syndrome may have difficulty breathing. If breathing problems are severe enough, sometimes a tracheostomy may be needed to be sure that your child gets the oxygen they need to grow and develop normally. All children with Treacher Collins syndrome should be monitored carefully in the early months of life to be sure there are no breathing concerns.
In addition, many children with Treacher Collins syndrome will have some degree of hearing loss in one or both ears. Children need to be evaluated early for hearing loss. If needed, children should be fitted for conductive hearing aids to improve hearing and help with normal speech development.
Diagnosis of Treacher Collins syndrome
The diagnosis of Treacher Collins syndrome is initially based on the characteristic appearance and physical exam findings. The diagnosis may be confirmed by a blood test to identify the abnormal Treacle gene.
Treatment of children with Treacher Collins syndrome is complex and is aimed at correcting the facial and jaw abnormalities, correcting the cleft palate, improving the eyelid tilt, treating obstructive sleep apnea and reconstructing the ears (if needed).
- Airway: In the first year of life, children with Treacher Collins syndrome should be evaluated for breathing difficulties. It is important for your baby to get enough oxygen to allow normal growth and development. Although not all babies with this syndrome need surgery to help with airway problems, some may require a tracheostomy. This is a surgically created opening in the neck into which a small tube is placed to help your child breathe. Tracheostomies are usually temporary.
- Palate surgery: The palate is typically repaired when the baby is between 9 and 12 months of age. Some surgeons advocate earlier repair, citing the potential for improved speech outcomes later in childhood. Others point out that earlier repair may adversely affect the way in which the palate and mid portion of the face grow over time. Although the ideal timing of palate surgery continues to be controversial, it seems that most surgeons now agree that choosing a time between 9 and 12 months of age balances those competing concerns regarding speech and facial growth. A variety of repair techniques have been described, and most of the commonly performed repairs lead to good results. The specific choice of technique is dictated by the type and extent of palate clefting observed in a particular baby.
- Eyelid surgery: The downward tilt of the eyelids can give your child a tired, sad appearance. The tilt can be corrected by raising the corners of the eyelids with a surgery called a lateral canthopexy. This surgery is usually done on an outpatient basis, meaning that your child is likely to go home the same day. Although the surgery can be done at any time, it is more successful if done later in childhood. It probably makes the most sense to wait to do this surgery until the appearance of the eyes becomes a concern to your child. Canthopexy surgery may also be combined with other surgeries your child may need in order to limit the number of times your child goes to sleep for surgery.
- Cheek bones: Children with Treacher Collins syndrome have missing or very small cheek bones. Our preference is for rebuilding your child’s cheek bones with bone grafts. This surgery is generally done around 9 years of age or later. In the late teenage years, if the cheek bones still appear too small, artificial cheek implants may be used build the cheek bones up further.
- Ear surgery: The ear deformities seen in Treacher Collins syndrome vary in severity. For the most severe ear deformities, ear reconstruction may be recommended. There are several different techniques for reconstructing missing or severely malformed ears in children. The best reconstructive option, and the one which promises the greatest likelihood of lasting a lifetime, is rebuilding the ear using your child’s own tissue. This type of ear reconstruction, also called “autologous reconstruction”, uses your child’s rib cartilage to build a new ear framework. This surgery is generally accomplished in 2-3 stages over 6-9 months. The ideal time for autologous ear reconstruction is 7-9 years of age. Surgery at this age ensures that there is enough cartilage to rebuild the ear. It also allows your child to be sufficiently mature to better understand and participate in the process. If ear reconstruction is only needed on one side, this timing also allows us to match the reconstructed ear to your child’s normal ear which will have nearly reached adult size by this time.
- Jaw surgery: Most children with Treacher Collins syndrome will need a combination of braces and jaw surgery to correct the abnormal position of the jaws and teeth. Corrective jaw surgery is most often done once the facial bones have stopped growing toward the end of adolescence. Facial bone growth is usually complete at 17-18 years old in young men and perhaps a bit earlier in young women. The treatment planning for corrective jaw surgery in children with Treacher Collins syndrome is complex and requires good communication between an experienced craniofacial surgeon and an orthodontist familiar with jaw surgery techniques.