Antley-Bixler Syndrome is a rare genetic disorder that is primarily characterized by distinctive malformations of the head and facial (craniofacial) area and additional skeletal abnormalities. For example, the disorder is typically associated with premature closure of the fibrous joints (cranial sutures) between particular bones of the skull (craniosynostosis). Many affected infants and children also may have a prominent forehead, underdeveloped midfacial regions (midfacial hypoplasia), protruding eyes (proptosis), and other craniofacial abnormalities. Additional skeletal malformations are usually present, such as fusion of certain adjacent bones of the arms (e.g., radiohumeral or radioulnar synostosis), long, thin fingers and toes (arachnodactyly), and bowing of the thigh bones. In addition, certain joints may become permanently flexed or extended in fixed postures (joint contractures), resulting in restricted movements.
Antley-Bixler Syndrome often appears to be inherited as an autosomal recessive trait. However, according to researchers, other cases may result from spontaneous (sporadic) genetic changes (mutations) that may be transmitted as an autosomal dominant trait.
