Treacher Collins Syndrome

Craniofacial anomaly characterized by an antimongoloid slant of the eyes, coloboma of the lid, micrognathia (can be severe), microtia and other deformity of the ears, hypoplastic zygomatic arches, and macrostomia. Conductive hearing loss and cleft palate are often present.

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Treacher-Collins-Franceschetti Syndrome; Berry-Treacher-Collins Syndrome; Mandibulofacial Dysostosis; TCOF-I Syndrome.

1:10,000 live births

An autosomal dominant transmission with high penetrance and variable expressivity. The gene is localized on the long arm of chromosome 5 (in 5q32-q33.1 locus region, also termed TCOF1 locus) and produces a protein called the “treacle” gene.

Dysmorphogenesis of the first and second embryonal branchial arch systems. It has been postulated that it results from a defect in a nucleolar trafficking protein that is critically required during human craniofacial development. Interestingly enough, the facial features are strikingly similar to those observed with vitamin A toxicity in both animals and humans born of a mother who took 2000 IU of vitamin A daily as a supplement during pregnancy.

The diagnosis of these syndromes is based on the clinical features. The radiographic studies may show poorly developed supraorbital ridges, hypoplastic malar bones, hypoplasia of mandible, and flat or aplastic coronoid and condyloid processes. Prenatal diagnosis is possible by ultrasonographic examination (by the 20th week) and by molecular biology on chorionic villus sample (as source of fetal DNA). All the mutations currently reported suggest haploinsufficiency as the molecular mechanism underlying the disorder. Laboratory and radiological findings, which include supraorbital ridges, hypoplastic malar bones, hypoplasia of mandible, aplastic coronoid and condyloid processes, and abnormal cranial base (basilar kyphosis).

The eyes show several anomalies: antimongoloid obliquity of palpebral fissures, coloboma of outer portion lower lids, with a deficiency of cilia, absence of the lower lacrimal points, microphthalmia. Flattening of the cheeks. Facial features: malar hypoplasia; hypoplastic zygomatic arches; antimongoloid slant; lower eyelid coloboma; microphthalmia; vision loss; strabismus; partial absence of lower eyelashes; nystagmus; atresia of external auditory meatus; microtia; malpositioning or maldevelopment of the pinna. Mouth: cleft palate, mandibular hypoplasia, macrostomia, absence of parotid gland. Other clinical anomalies: cardiovascular defects; cervical vertebral malformations; renal anomalies; choanal atresia; limb malformations; early failure to thrive; learning disabilities in early life; chronic respiratory insufficiency; cryptorchidism; psychological problems and social stigma as a consequence of facial deformity; sleep apnea syndrome and sudden death; conductive hearing loss; mental retardation.

Management of the airway is expected to be difficult. Because of the mandibular retrusion and condylar hypoplasia, tracheal intubation with a fiberoptic laryngoscope is necessary. Sometimes a tracheostomy may be required. Physical examination is directed toward the cardiovascular system, lungs, and upper airway. Laboratory data: blood chemistries, blood group, hemoglobin, and coagulation studies.

The anesthetic management is a function of the severity of the malformation and of the surgical procedure (oral or nasotracheal intubation). The major problem in anesthesia is the maintenance of a free airway and tracheal intubation. Difficult airway problems must be anticipated and precautions should be taken to manage the patient safely. The maintenance of spontaneous respiration is highly recommended until the trachea has been intubated and lung ventilation confirmed. Use of a laryngeal mask may help. The reason for the demise of the tracheostomy are anesthetic experience, availability of flexible fiberoptic bronchoscope, requirement of a prolonged postoperative endotracheal intubation, and the availability of intensive care facilities (problem may occur in this area such as occlusion of a nasotracheal tube by mucus). Blood loss may be important during craniofacial reconstructive surgery and requires (invasive or noninvasive) monitoring of hemodynamic parameters, estimation of blood loss, arterial blood gas, and electrolyte analysis. Postoperative care often requires transfer to intensive care unit.

Use of muscle relaxants must be avoided until the airway is secure and lung ventilation is confirmed.

Aksu Stockhausen Syndrome: This autosomal dominant medical condition is defined by the association of brachial arch defects. Characterized by the presence of anotia/microtia, microstomia, preauricular pits, respiratory distress, pharyngeal abnormality, hearing loss, sacral sinus/dimple, hypertonia, spasticity, and muscle rigidity. A proper evaluation of the airway must be done to eliminate the possibility of a difficult airway during face-mask ventilation and tracheal intubation. The potential for hyperkalemia following the administration of succinylcholine must be considered if hypertonia is present.

Franceschetti Syndrome (Franceschetti-Zwahlen-Klein Syndrome): Mandibulofacial dysostosis presenting at birth with cyanotic spells. Fish-like facial characteristics, hypoplasia of the mandible, receding chin, considerable overbite, high-arched palate, macrostomia, low-set ears. An autosomal dominant inheritance. The difference between this disorder and Treacher Collins is believed to be the absence of flattening of the malar bones.

Goldenhar Syndrome: Common birth defect of vascular origin involving first and second branchial arch derivatives, resulting mainly in hemifacial microsomia with absent ear, eye, and vertebral anomalies. Usually associated with cardiovascular anomalies, including ventricular septal defect, atrial septal defect, patent ductus arteriosus, tetralogy of Fallot, and coarctation of the aorta. Arnold-Chiari syndrome and hydrocephalus have been reported. Severe to major anesthetic implications, especially the airway (unilateral hypoplasia of the facial bones and muscles). Epibulbar dermoids. Limited mouth opening, micrognathia, cleft palate.

Miller Syndrome: Postaxial acrofacial dysostosis. Characterized by distinctive major craniofacial malformation (micrognathia, underdeveloped cheekbones, severe LeFort II malformation, and cleft palate) requiring tracheostomy at birth for breathing obstruction. Limb defects include underdevelopment of the ulna and radius (incomplete limb development). Miller syndrome patients are of normal intelligence.