Antley-Bixler syndrome is a rare genetic disorder characterized by a specific set of craniofacial and skeletal abnormalities. It is a condition present from birth, affecting the development of the skull, face, and limbs.
Key Characteristics
Based on the provided reference, Antley-Bixler syndrome is defined by several distinctive features. The most prominent involve the head and face, along with notable limb anomalies.
Craniofacial Abnormalities
Individuals with Antley-Bixler syndrome typically present with a range of craniofacial features, including:
- Craniosynostosis: Premature fusion of skull bones, leading to abnormal head shape.
- Frontal bossing: An unusually prominent forehead.
- Flat facies: A flattened appearance of the face.
- Severe mid-face hypoplasia: Underdevelopment of the middle part of the face.
- Proptosis: Bulging of the eyes.
- Flattened nasal bridge: The bridge of the nose is noticeably flat.
- Pear-shaped nose: The nose has a characteristic pear-like shape.
- Choanal stenosis/atresia: Narrowing or blockage of the nasal passages connecting the nose to the throat, making breathing difficult.
- Long philtrum: An elongated area between the base of the nose and the upper lip.
- Small dysplastic ears: Ears that are small and abnormally formed.
Skeletal Anomalies
Beyond the head and face, the syndrome also affects the limbs:
- Radiohumeral synostosis: The radius (forearm bone) is fused to the humerus (upper arm bone), limiting elbow movement.
- Bowing of the femurs: The thigh bones (femurs) are curved or bowed.
These features collectively constitute the clinical presentation of Antley-Bixler syndrome, as described in the reference.
