Asphyxiating thoracic dystrophy-Jeune syndrome (JS) is a rare autosomal recessive disease characterized by small thorax and short limb dwarfism. Besides the clinical variability, prognosis also differs greatly among patients. Pulmonary involvement is predominant in some cases whereas renal involvement is much more evident in others. We aimed to investigate the clinical variability and prognosis in 13 patients with JS from 11 families. Two of them, who had been diagnosed in the prenatal period were assessed by autopsy findings. All patients had a bell-shaped or long narrow short thorax and brachydactyly at varying degrees from mild to severe. Short stature was common feature emerging in the postnatal period. One patient had atlantoaxial instability and spinal cord compression which have not been reported in JS before. In the postnatal follow up of 11 patients, respiratory distress was observed in eight patients and proved lethal in six, one patient died of chronic renal failure, and the remaining four patients were still alive at the end of the study. Patients were classified into three groups consisting of severe pulmonary involvement, renal involvement, and mild form in terms of prognosis. Patients with severe pulmonary involvement had bell -shaped thorax and mild brachydactyly, the one patient with renal involvement had long narrow thorax and severe brachydactyly, and patients with mild involvement presented with polydactyly and moderate to severe brachydactyly. It is important to establish a correct diagnosis both in severe and mild forms since JS might recur within the same family. © 2009 Wiley-Liss, Inc.