Antley-Bixler syndrome (ABS), also known as trapezoidocephaly-synostosis syndrome, is a rare autosomal dominant or recessive condition characterized by craniosynostosis and extra-cranial synostoses. Mid-facial hypoplasia is also common.
It is a very rare condition with only 50 cases described in the global literature up to 2006 3.
- limb synostoses e.g. radioulnar, radiohumeral
- mid-face hypoplasia - commonly associated with airway obstruction
- congenital heart disease
- renal maldevelopment e.g. agenesis
- POR mutation only: congenital adrenal hyperplasia and ambiguous genitalia
Mutations in two separate genes FGFR2 and POR have been found to produce the Antley-Bixler syndrome phenotype.
FGFR2 is inherited in an autosomal dominant manner and POR is in an autosomal recessive manner.
Treatment and prognosis
Neonatal mortality is up to 80%, with usual cause of death respiratory compromise. However as the child ages, prognosis improves.
History and etymology
First case was described by R Antley and D Bixler in 1975 3.
- 1. Ko JM. Genetic Syndromes Associated with Craniosynostosis. (2016) Journal of Korean Neurosurgical Society. 59 (3): 187-91. doi:10.3340/jkns.2016.59.3.187 - Pubmed
- 2. Lahiri S, Ghoshal B, Nandi D. A case of antley-bixler syndrome. (2012) Journal of clinical neonatology. 1 (1): 46-8. doi:10.4103/2249-4847.92232 - Pubmed
- 3. Antley R, Bixler D. Trapezoidocephaly, midfacial hypoplasia and cartilage abnormalities with multiple synostoses and skeletal fractures. (1975) Birth defects original article series. 11 (2): 397-401. Pubmed