Metatropic Dysplasia, Jeune (Asphyxiating Thoracic) & Ellis-van Creveld

A neonate with a very narrow, bell-shaped thorax, short ribs and respiratory distress has Jeune syndrome, the asphyxiating thoracic dysplasia, now classified within the short-rib thoracic dysplasias, which are often ciliopathies. The threat to life is thoracic insufficiency: the small, short-ribbed thorax restricts lung growth and ventilation, producing a restrictive respiratory failure that can be fatal in infancy. The phenotype is highly variable, from mild to lethal, and earlier antenatal presentation with greater femoral shortening and bowing predicts a worse prognosis. There is also associated progressive renal, and hepatic, disease, which must be monitored. The related syndromes I would consider are along a spectrum: Ellis-van Creveld syndrome, or chondroectodermal dysplasia, which is autosomal recessive and combines postaxial polydactyly, short acromesomelic limbs, ectodermal defects of the nails and teeth, and congenital heart disease, classically a single atrium - it can overlap with a narrow thorax; and metatropic dysplasia, a changing-pattern dysplasia that begins short-limbed and becomes short-trunked, with a coccygeal tail-like appendage, platyspondyly, dumbbell-shaped long bones and severe progressive kyphoscoliosis, where the small thorax and the spinal deformity together threaten respiration. Management is multidisciplinary and complication-directed: for Jeune, respiratory support and thoracic-expansion surgery for the thoracic insufficiency plus renal monitoring; for Ellis-van Creveld, cardiac assessment and repair with polydactyly and dental care; and for metatropic, management of the severe kyphoscoliosis and any cervical instability with respiratory care - all with genetic diagnosis and counselling.