Carpenter Syndrome (Acrocephalopolysyndactyly Type II)

Extremely rare; global estimate: 1:1,000,000 births

Over 100 reported cases

Airway obstruction

Difficult mask ventilation and/or difficult intubation

Increased ICP from craniosynostosis

Coexisting congenital anomalies, especially cardiac

Manifestation:

• Craniosynostosis

• Polysyndactyly

• Cardiac defects

• Obesity

• Maxillary or mandibular hypoplasia

Craniosynostosis usually with metopic and sagittal sutures (midline suture fusion)

Cardiac defects in up to 50% of cases (tetralogy of Fallot, transposition of great vessels, pulm artery stenosis, VSD, and ASD)

Other features: Brachydactyly, cognitive impairment, umbilical hernia, macrosomia, cryptorchidism in males, molar agenesis, high-arched narrow palate, broad cheeks, shallow supraorbital ridges, hypertelorism, and genu valgum

Currently not elucidated

Autosomal recessive

Mutation in RAB 23 gene on chromosome 6P12.1-q12 shown in most cases; at least five different mutations in RAB 23 gene

Some cases of mutation in MEGF8 gene