ANTLEY-BIXLER SYNDROME

Antley-Bixler syndrome is a rare chondrodysplasia characterized by multisynostotic osteodysgenesis, long bone fracture, severe midfacial hypoplasia, arachnodactyly, femoral arching, ulnar arching, vertebral anomalies and contractures secondary to synostosis (1).

· Sporadic mutations in some cases (2-4).

· Association with steroidogenesis (luteomas, congenital adrenal hyperplasia, and hyperandrogenism) during pregnancy (5-7).

· Recurrence in siblings has been described suggesting a possible autosomal recessive inheritance (8,9).

This syndrome consists of multiple malformations including:

• Multisynostotic osteodysgenesis with long bone fractures.
• Femoral bowing.
• Joint contractures (radiohumeral contractures secondary to synostosis). Contractures (92.5%) and radiohumeral synostosis (100%) (6).
• Midface hypoplasia.
• Abnormal head shape with shortening of the cranial base and craniosynostosis.
• Urogenital anomalies include, hydronephrosis, renal duplication, labial hypoplasia, elongated clitoris and lack of testicular descent.

ULTRASOUND

Link to Ultrasound

PROGNOSIS

Overall prognosis is poor, however neonatal outcome can be improved with proper treatment.
85% die shortly after birth, usually secondary to pulmonary hypoplasia, choanal atresia, laryngeal atresia or stenosis.

REFERENCES

1. Machado LE, Osborne NG, Bonilla-Musoles F. Antley-Bixler syndrome. J Ultrasound Med 2001;20:73-77.
2. Chabchoub A, Siala-Gaigi S, Marrakchi Z et.al. The Antley-Bixler syndrome. A case without radiohumeral synostosis. Genet Couns 1998;9:113-118.
3. Reardon W, Smith A, Honour JW et.al. Evidence for digenic inheritance in some cases of Antley-bixler symdrome? J Med Genet 2000;37:26-32.
4. Roth C, Hinney B, Peter M et.al. Features of Antley-bixler syndrome in an infant born to a mother with pregnancy luteoma. Eur J Pediatr 2000;159:189-192.
5. Warmann S, Roth C, Gluer S et.al. Congenital adrenal hyperplasia associated with maternal pregnancy luteoma and the Bixler syndrome. J Pediatr Surg 2000; 35:528-530.
6. Jacobson RL, Dignan Peter St John, Miodovnik M et.al. Antley Bixler Syndrome. J Ultrasound Med 1992;11:161-164.
7. Antley R, Bixler D. Trapezoidocephaly, midfacial hypoplasia and cartilage abnormalities with multiple synostoses and skeletal fractures. Birth Defects 1975;11:397.
8. Yasui Y, Yamaguhi A, Itih Y et.al. The first case of Antley-Bixer syndrome with a consanuinity in Japan. Jpn J Hum Genet 1983;28:215.
9. Schinzel A, Savoldelli G, Briner J et.al. Antley Bixler syndrome in sisters: A term newborn and a prenatally diagnosed fetus. Am J Med Genet 1983;14:139.