Antley-Bixler syndrome

Synonyms

Trapezoidocephaly synostosis syndrome
Multisynostotic osteodysgenesis with long bone fractures
Osteodysgenesis, multisynostotic with fractures

Overview

A rare genetic disorder characterized by premature closing of skull bones, choanal atresia and craniofacial and limb abnormalities.

Symptoms

The signs and symptoms vary significantly from person to person but may include

  • Craniosynostosis
  • Midface hypoplasia (underdeveloped middle region of the face)
  • Protruding eyes, Low-set
  • Unusually-formed ears
  • Choanal atresia or stenosis (narrowing)
  • Fusion of adjacent arm bones (synostosis)
  • Joint contractures
  • Bowing of the thigh bones
  • Urogenital (urinary tract and genital) abnormalities
  • Brachycephaly
  • Frontal bossing
  • Large anterior fontanel
  • Premature closing of skull bones
  • Midfacial hypoplasia
  • Depressed nasal bridge
  • Drooping eyelids
  • Choanal stenosis
  • Choanal atresia
  • Dysplastic ears
  • Stenotic external auditory canals
  • Radiohumeral bone fusion
  • Joint contractures
  • Inability to extend fingers
  • Decreased range of motion at wrists
  • Decreased range of motion at hips
  • Decreased range of motion at knees
  • Decreased range of motion at ankles
  • Arachnodactyly
  • Enlarged interphalangeal joints
  • Increased numbers of flexion creases
  • Distal tapering of fingers
  • Narrow nails
  • Femoral bowing
  • Femoral fractures
  • Rocker-bottom feet

Causes

The exact underlying cause of Antley Bixler syndrome is unknown in many cases; however, some are due to changes (mutations) in the FGFR2 gene or the POR gene. There appear to beautosomal dominant and autosomal recessive forms of the condition.

Prognosis

One third of affected children are alive, and some have had quite satisfactory development . Some patients with the syndrome have normal intelligence, which suggests a normally developing brain.

Treatment

Treatment is based on the signs and symptoms present in each person.

Resources

  • NIH