Treacher Collins Syndrome
Introduction
Corrective surgery in children with Treacher Collins syndrome is a complex subspecialty of facial reconstructive surgery that requires experts of several different specialties working together. Treatment should be performed by experienced craniofacial surgeons intimately involved with a craniofacial center. All of our surgeons are experienced in the treatment of children with Treacher Collins syndrome and function as Craniofacial Surgeons, Plastic & Reconstructive Surgeons, and Oral & Maxillofacial Surgeons for the New Jersey Institute for Craniofacial Surgery. Dr. Amato authored one of the definitive book chapters on the surgical reconstruction of Treacher Collins syndrome together with Dr. Jeffrey Posnick.
The initial reference to Treacher Collins syndrome was made in 1846 by Dr. Allen Thompson, a British physician. However, Dr. Edward Treacher Collins, an English ophthalmologist, first described the essential features of the syndrome in 1900. It was not until 1949 that the first extensive description of the condition was given by Dr. Franceschetti and Dr. Klein (Swiss ophthalmologists). They coined the term “mandibulofacial dysostosis.” In 1971, Dr. Paul Tessier, a famous craniofacial surgeon, described the syndrome as a confluence of facial clefts—“the bilateral confluence of facial clefts 6, 7, and 8.”
This history helps to explain the many different names that are used to refer to this syndrome:
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Franceschetti -Klein syndrome (French and European literature)
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Mandibulofacial dysostosis
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Treacher Collins-Franceschetti syndrome
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Zygo-auro-mandibular dysplasia
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Tessier clefts 6, 7, and 8
Nager syndrome is sometimes confused with Treacher Collins syndrome. Although children with Nager syndrome may have many of the same facial features of children with Treacher Collins syndrome, it is a distinct syndrome with different genetics and features. This is an important distinction that must be made when treating these children.
Treacher Collins syndrome affects the development of the bones and soft tissues of the face. The signs and symptoms can range from almost unnoticeable to severe and life-threatening. A typical presentation can involve the following issues.
Presentation of Treacher Collins
Facial Bones
The cheek bones, upper and lower jaws, and chin are the most noticeably underdeveloped facial bones. The underdeveloped lower jaw typically causes the lower teeth to fall behind the upper teeth when the mouth is closed (Class II occlusion) and there also tends to be an opening between the upper and lower front teeth when the mouth is fully closed (anterior open bite). In severe cases, the underdeveloped facial bones can interfere with a child’s ability to breathe properly, creating serious respiratory problems requiring urgent treatment.
Nose
The bridge of the nose is mildly to moderately increased in width, and a bump is always present on the dorsum. The length of the nose may be normal or long and the tip often droops with a lack of adequate projection.
Eyes
Children with Treacher Collins syndrome often have downward slanting eyes, sparse or absent eyelashes, a notch in the lower eyelids called a coloboma, as well as disturbances in the upper eyelids and eyebrows.
Ears
Children with Treacher Collins syndrome commonly have absent, small, or malformed ears. About 50% of all affected individuals have some degree of hearing loss caused by a malformation of the ear canal resulting in a disturbance in the transmission of sounds or by defects of the bones in the middle ear affecting sound transmission. These types of hearing issues are referred to as conductive hearing losses because there is a disturbance in the conduction of sound to the inner ear. This is in contrast to sensorineural hearing loss seen in other syndromes, which is a disturbance in the processing of sounds that reach the inner ear.
Soft Tissues
The soft tissues in the cheek and eye area are typically deficient. The corners of the mouth may extend farther laterally into the cheeks than normal (macrostomia).
Cleft Palate
Some children are also born with an opening in the roof of the mouth called a cleft palate.
Frequency of Occurrence
Treacher Collins syndrome is estimated to occur in approximately 1 in 50,000 births. Between 80 and 90% of the time, Treacher Collins syndrome is caused by a mutation in the TCOF1 gene. The proteins produced from the TCOF1 gene have been reported to play important roles in the early development of bones and other tissues of the face. The TCOF1 gene helps to produce ribosomal RNA (rRNA), which helps to build proteins in cells. Although the process is not clear at this point in time, it is speculated that the affected rRNA somehow disturbs the development of the affected facial tissues.
In most instances, Treacher Collins syndrome is an autosomal dominant condition, meaning that only one copy of the altered gene in each cell is sufficient to cause the disorder. About 60% of cases result from new mutations in the gene occurring in people with no history of the disorder in their family. In the remaining cases, the altered gene is inherited from an affected parent.
A person with Treacher Collins syndrome has a 50% chance with each pregnancy of passing the syndrome on to the child. But the severity of the syndrome can vary among members of the same family. It is possible to ensure that an individual with Treacher Collins syndrome does not pass the syndrome to a child by using in-vitro fertilization and selecting an embryo for implantation that does not have the syndrome.
Treatment Overview
Treatment should be tailored to the specific needs of each individual. Surgical treatment is divided into six stages.
Stage I: Functional Emergencies at Birth
Children with Treacher Collins syndrome face three main urgent problems at birth: difficulty breathing , difficulty feeding, and potential vision issues.
Breathing and Feeding Issues
The first priority to address in infancy is breathing. Because of the small mandible, nasal obstruction, and possible cleft palate, breathing issues can be significant. The significance of the breathing and feeding difficulties depends on many factors, including:
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Premature birth
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Significance of the abnormalities
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Whether a cleft palate is present
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Associated medical issues
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Size and weight of the child
Typically, a treatment algorithm is followed for breathing and feeding issues in order to determine the least invasive procedure that will effectively relieve the difficulty. However, treatment will vary for each patient, each doctor, and each hospital. Naso-endoscopy, bronchoscopy, and swallow studies may be performed to determine the most appropriate treatment. Below are typical algorithms used to treat oral-facial related breathing and feeding difficulties in infants with Treacher Collins syndrome.
Typical Breathing Treatment Algorithm
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Prone positioning: lying flat with chest down
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Nasopharyngeal airway: placement of a tube in the nose to help breathing
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Tongue-lip adhesion: a minor procedure to temporarily place the tongue in a more forward position by securing it to the lower lip
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Distraction of the mandible: surgery of the lower jaw and the application of a special device that is used to gradually advance the lower jaw forward over 1 to 2 weeks
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Tracheostomy: placement of a breathing tube directly into the trachea bypassing the upper airway (may be only temporary)
Typical Feeding Treatment Algorithm
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Correction of any breathing issues
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Observation of child feeding and monitoring of weight trends
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Swallowing study to evaluate for coordination of muscles and aspiration
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Adjustment of thickness of feeds and use of special feeding bottles
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Nasogastric tube: a small tube passed through the nose into the stomach
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G-tube: a tube that goes through the skin of the abdomen directly into the stomach
Vision Issues
If corneal exposure is present, eyelid reconstruction may be required.
Stage II: Cleft Palate Repair
If present, a cleft palate is repaired at around 1 year of age.
Stage III: Ear Reconstruction
Reconstruction of the ear typically begins around 6 years of age.
Stage IV: Zygomatic (Cheek) Reconstruction
Reconstruction of the cheek typically begins around 7 years of age.
Stage V: Corrective Jaw Surgery
Corrective jaw surgery is performed when facial growth is completed at approximately 14 to 17 years of age.
Stage VI: Corrective Nasal Surgery (Rhinoplasty)
Rhinoplasty, or corrective nasal surgery, should be performed after corrective jaw surgery has been completed.
References
Franceschetti A, Klein D: The mandibulofacial dysostosis: a new hereditary syndrome. Acta Ophthalmol. 1949;27:144.
Gorlin RJ, Cohen MM, Levin LS. Syndromes of the Head and Neck. New York: Oxford University Press, 1990.
Katsanis SH, Jabs EW. Treacher Collins Syndrome. [Internet]. Initial Posting: July 20, 2004; Updated: August 30, 2012. In: Pagon RA, Adam MP, Ardinger HH, et al., eds. GeneReviews® [Internet]. Seattle, WA: University of Washington, Seattle, 1993-2015. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1532/.
National Library of Medicine (U.S.). Genetics Home Reference. [Internet]. Bethesda, MD: The Library; 2015 Feb 2. Treacher Collins syndrome; [reviewed 2012 June; cited 2015 Feb 4] [1 screen]. Available from: http://ghr.nlm.nih.gov/condition/treacher-collins-syndrome.
Posnick, JC, Amato, J. Treacher Collins syndrome: evaluation and staging of reconstruction. In: Fonseca R, ed. Oral and Maxillofacial Surgery. 2nd ed. Vol III. 45:936-960. Elsevier, 2009.
Tessier P: Vertical and oblique facial clefts (orbitofacial fissures. In: Mustarde JC, ed. Plastic Surgery in Infancy and Childhood. Philadelphia: Saunders, 1971:94.
Trainor PA, Dixon J, Dixon MJ. Treacher Collins syndrome: etiology, pathogenesis and prevention. Eur J Hum Genet. 2009 Mar;17(3):275-283.
Treacher Collins E: Case with symmetric congenital notches in the outer part of each lid and defective development of the malar bones. Trans Ophthalmol Soc UK. 1900;20:109.