Antley-Bixler syndrome

Antley-Bixler syndrome is a rare and severe congenital disorder that causes malformations across much of the skeleton and other body systems, typically identified at birth or prenatally. It usually follows an autosomal recessive inheritance pattern, meaning an affected child inherits one defective gene copy from each parent while carriers of a single copy show no symptoms. Characteristic features include a flattened forehead, prematurely fused skull joints, underdeveloped facial bones and bowed limb bones, and the condition can also involve heart malformations, bulging eyes, thin spider-like fingers, and blockages of the nasal, anal or vaginal passages. Two distinct genetic causes have been identified: mutations in the FGFR2 gene, which governs skeletal development and skull suture fusion, and mutations in the POR gene, which affects steroid hormone production and can contribute to genital malformations, suggesting the syndrome can arise from more than one underlying genetic mechanism.