Treacher Collins Syndrome
Description of Treacher Collins Syndrome
Treacher Collins Syndrome or Mandibulofacial synostosis effects the size and shape of the ears, cheek bones, and upper and lower jaws. This condition is the result of an autosomal dominant gene.
Preoperative frontal view shows patient with Treacher Collins Syndrome. Postoperative frontal view of same patient after completion of the osteotomies with the device in place. Distraction begins 5-7 days after insertion of the device at a rate of 1mm per day. Preoperative lateral view of patient with tracheostomy showing retrognathic microgenia. Postoperative lateral view showing vertical and horizontal lengthening. After 5 weeks of distraction, the patient was able ultimately to discard the tracheostomy.
Characteristics of Treacher Collins Syndrome
The anomalies most often associated with this Treacher Collins Syndrome include:
- Facial cleft (Tessier 6-7-8 cleft)
- Hypoplasia of the cheeks and mandible bilaterally
- Colobomas (or congenital scar) of the eyelids
- Downward-sloping palpebral fissures
- Poorly developed supraorbital rims and cheeks
- Receding chin
- Malformation of the ear
Although the severity of Treacher Collins Syndrome can vary, the problems faced by a child with Treacher Collins Syndrome can be quite complicated and require the attention of a professional with experience with these types of patients. In the early years, patients often have difficulty maintaining an open airway and may need some assistance with obtaining adequate nutrition. In most cases as the patient grows and matures structurally, these problems are alleviated. Also,the malformation of the upper and lower jaws most often results in a malocclusion of the bite. A Treacher Collins Syndrome patient can also have impaired hearing depending upon the extent to which the deformity effects the formation of the ears. There may be a cleft of the palate as well.
Causes of Treacher Collins Syndrome
Treacher Collins Syndrome is caused by autosomal dominant inheritance of the “Treachle gene” which is located on chromosome 5. The children of a parent with Treacher Collins Syndrome have a 50% risk of having Treacher Collins Syndrome. If the parents of the affected child are not effected by Treacher Collins Syndrome, the chances of a sibling having Treacher Collins Syndrome is minimal.
Expectations and Treatment of Treacher Collins Syndrome
Children with Treacher Collins Syndrome may have hypernasal resonance due to the presence of the cleft palate. Although most patients with Treacher Collins Syndrome exhibit normal intelligence, some patients with Treacher Collins Syndrome can have a decreased intellectual capacity. They may experience difficulty breathing and eating which they typically outgrow.
Treacher Collins Syndrome patients generally require extensive care in the first few years of life. They may require the placement of a tracheostomy tube to assist them with breathing. A gastrostomy tube is used in the more severe cases to help the patient obtain adequate nutrition and energy for growth.
Typically, Treacher Collins Syndrome patients outgrow these problems and these tools are removed. Due to the severe underdevelopment of their upper and lower jaws, Treacher Collins Syndrome patients usually require both mandibular and maxillary surgery to correct these deficits. The mandible can be corrected either by applying a rib graft to the mandible or through a technique known as distraction osteogenesis. The technique which will provide the best result will be decided on a cases by case basis by the craniofacial surgeon.
With treatment of the jaws, it is necessary to obtain good orthodontic care to correct the malocclusion the deformity will produce. Nasal surgery may also be required to compensate for the deficient upper and lower jaws. In cases where colobomas exist, the Treacher Collins Syndrome children usually need eyelid reconstruction by a specialized pediatric ophthalmologist.
Treacher Collins Syndrome
Franceschetti-Zwahlen-Klein syndrome, known as Treacher Collins Syndrome, is a genetic disorder characterized by craniofacial deformities. In every ten thousand births, there is at least one person who is born with this deformity. Edward Treacher Collins first explained this deformity in 1900 and it is named after him. Medical studies suggest that Treacher Collins Syndrome is inherited.
Treatment of Treacher Collins Syndrome
Treatment aims at addressing difficulties encountered in Treacher Collins Syndrome, such as feeding, hearing and breathing problems. In several cases, a tracheostomy, or ‘breathing hole’, is placed in the neck that allows the child to breathe, as the jaw may be very small and may pose breathing and feeding difficulties in newborns.
One in every ten children is born with this kind of birthmark, and between fifty and sixty percent of them usually require some form of treatment.
A newborn with Treacher Collins Syndrome can be treated with special feeding techniques and can be operated on a little later in life. Children suffering from Treacher Collins Syndrome also undergo multiple surgeries – including the reconstruction of the outer ear, repairing of eyelid deformities and cheekbone and jaw enhancement.
Pre-Natal Testing
Many parents choose to undergo prenatal testing. To detect Treacher Collins Syndrome, testing of fetal cells, amniotic fluid and amniotic membranes is conducted. Genetic counseling and prenatal diagnosis helps parents to make intelligent decisions regarding the pregnancy. .
If it is determined that a parent has a disposition toward Treacher Collins Syndrome, they may opt to use donated eggs and sperm in order to conceive. Pre-implantation is one of the latest techniques that incorporates invitro fertilization and genetic testing of the resulting embryos, before implanting those embryos that are not found to have the abnormal gene.
Medical Breakthroughs
A team of doctors in Kansas, Missouri has made a breakthrough in identifying the cellular origins of the craniofacial abnormalities occurring in Treacher Collins syndrome that include ear, nose, upper and lower lip abnormalities, including cleft palateIf it is determined that a parent has a disposition toward Treacher Collins Syndrome, they may opt to use donated eggs and sperm in order to conceive. Pre-implantation is one of the latest techniques that incorporates invitro fertilization and genetic testing of the resulting embryos, before implanting those embryos that are not found to have the abnormal gene.
The observations of the Proceedings of the National Academy of Sciences show that the craniofacial anomalies of Treacher Collins syndrome arise mainly due to the increased rate of cell death that leads to the inefficiency to produce sufficient neural crest cells. The team also discovered that a small amount of neural crest cells produced have compromised reproductive capacity.
When these findings are translated to human development within the first three to eight weeks of pregnancy, similar extensive cell death results with the inability to produce sufficient neural crest cells and ultimately leads to deformities like those found in Treacher Collins Syndrome.
