Etiology:

• It is a rare autosomal dominant congenital disorder characterized by craniofacial deformities
• Associated with TCOF-1 gene (treacle gene) chromosome 5 mutation
• Due to stapedial artery defects, growth of craniofacial structures derived from the first and second pharyngeal arch, groove, and pouch are diminished symmetrically and bilaterally

Clinical:

1. Facial features:

• Downward slopping of palpebral features
• Underdeveloped zygomatic-maxillary complex
• Colobomas of lower eyelid (missing piece of tissue)
• Middle ear atresia
• Lower set ears with deformed pinna
• Orofacial clefts

2. Oral features:

• Macrostomia
• Cleft palate
• High arched palate
• Open bite (apertognathia)
• Mandible hypoplasia

Prenatal diagnosis:

• Mutations can be detected in chorionic villus sampling or amniocentasis
• Ultrasonography to detect craniofacial abnormalities later in pregnancy

X-ray:

• Decreased slopping of orbital floor
• Aplasia/ hypoplasia of zygoma
• Obtuse mandible angle
• Lateral cephalogram:
  • Broad curve of mandible
  • Flat condylar and coronoid process

Management:

• Hearing aids
• Surgery – Ophthalmological, maxillofacial, orthodontic

Prognosis:

• Treacher Collins syndrome patients grow to become functioning adults with normal intelligence. With proper management, life expectancy is approximately the same as in the general population

Differential diagnosis:

• Nager syndrome (acrofacial dysostosis) – distinguished by limb preaxial defects
• Miller syndrome – distinguished by limb postaxial defects
• Burn-Mckeown syndrome