Craniofacial Abnormalities and Genetic Disorders

Overview of Craniofacial Abnormalities and Genetic Disorders

• Treacher Collins syndrome is caused by a microdeletion of Chromosome 22q11.2 and is characterized by hypocalcemia, immunodeficiency, and congenital heart defects.
• TCOF1 gene mutation leads to malformation of the first and second branchial arches, otologic malformations, and preauricular fistulas.
• Apert syndrome, caused by a mutation of FGFR-2 gene, is characterized by craniosynostosis, midface hypoplasia, parrot-beaked nose, and severe symmetrical syndactyly.
• Branchio-oto-renal syndrome is characterized by branchial cleft anomalies, otologic malformations, and renal dysplasia.
• Robin sequence is characterized by abnormal facies, VPI, CLP, and cardiac anomalies caused by hemizygous microdeletion of 22q11.
• Stickler syndrome is characterized by abnormal facies, VPI, CLP, and cardiac anomalies caused by autosomal dominant transmission.
• Recurrent or persistent lip swelling, facial swelling, facial palsy, and furrowed tongue are seen in Melkersson-Rosenthal syndrome, which is considered a local immune response and vasomotor disturbance affecting the vasa vasorum of the vessels supplying the facial nerve and neighboring structures.
• Craniosynostosis is a primary defect of ossification at the sutures, which can cause skull growth restriction and increase intracranial pressure.
• Primary failure of brain growth can cause early fusion of sutures and secondary craniosynostosis, while intrauterine space constraints may contribute to the premature fusion of sutures in fetal skulls.
• Microcephaly and its causes, such as vitamin D deficiency, renal osteodystrophy, hypercalcemia, and rickets, can also contribute to craniofacial abnormalities.
• Surgery is not recommended for patients without increased intracranial pressure until the shape of the head does not improve by age 2-4 months, and cosmetic surgery is typically performed in infants aged 3-6 months.
• Genetic disorders causing craniofacial abnormalities have different modes of inheritance, such as autosomal dominant, autosomal recessive, and sporadic mutations, and can affect various parts of the face and body.