First described in 1950, Larsen syndrome (LS) is a rare hereditary condition, characterised by multiple joint dislocations and characteristic facial, hand and feet abnormalities. Both autosomal dominant and recessive forms exist, although the former is much more common. The incidence of the disease is 1:100,000, with equal gender distribution.
The autosomal dominant form of the disease is caused by mutations of the gene encoding filamin B, in a region containing human type VII collagen. This leads to abnormal collagen fibre formation, resulting in musculoskeletal and cardiac anomalies. The vertebrae are affected, causing cervical spine instability and kyphoscoliosis. Joints are prone to dislocation. Cardiac abnormalities can exist. Respiratory abnormalities occur due to a decreased rigidity of cartilages in the airway and rib cage, leading to laryngotracheomalacia, bronchomalacia and lung hypoplasia. Repeated surgical interventions for spinal and musculoskeletal abnormalities are common, warranting careful anaesthetic evaluation of the airway, cervical spine, cardiovascular, respiratory and neurological function. Despite the multisystem organ involvement, patients can have productive lives with early corrective surgery and support.