Freeman-Sheldon syndrome

Freeman-Sheldon syndrome (FSS), also known as distal arthrogryposis type 2A (DA2A), whistling face syndrome, or craniocarpotarsal dystrophy, is a rare congenital disorder characterized by multiple joint contractures (arthrogryposis), distinctive facial features, and skeletal abnormalities. The condition was first described by Freeman and Sheldon in 1938. It is considered the most severe form of the distal arthrogryposes. The hallmark facial features include a very small, pursed mouth (microstomia) that gives the appearance of whistling, a flat midface, prominent forehead, deep-set eyes, a broad nasal bridge, long philtrum, and H-shaped dimpling of the chin. The hands typically show ulnar deviation of the fingers, camptodactyly (permanently bent fingers), and adducted thumbs (thumbs held across the palm). Clubfoot (talipes equinovarus) is very common. Affected individuals may also experience scoliosis, short stature, and speech and swallowing difficulties due to the restricted mouth opening. Intelligence is usually normal, though some individuals may have mild developmental delays. The musculoskeletal, craniofacial, and respiratory systems are primarily affected. Respiratory complications can occur due to restrictive chest wall mechanics and difficulty managing secretions. Anesthesia carries increased risk due to airway management challenges related to the small mouth and potential for malignant hyperthermia. Treatment is multidisciplinary and symptomatic, including surgical correction of contractures and clubfoot, physical and occupational therapy to improve joint mobility, and craniofacial interventions to improve mouth opening. Speech therapy may be beneficial. Orthopedic management is often required throughout childhood. There is no cure, but with appropriate management, many individuals lead productive lives.

Common questions about Freeman-Sheldon syndrome