Metatropic dysplasia: clinical and radiographic findings in 11 patients demonstrating long-term natural history.

We report on the largest long-term follow-up study in metatropic dysplasia incorporating data collected over a 37-year period. Case summaries from 11 patients are presented, ranging from 20 weeks of gestation to age 70 years, characterizing the natural history. All patients were seen through the Victorian Clinical Genetics Service and the Southern Cross Bone Dysplasia Centre. Our data lend little support for the current clinical classification of metatropic dysplasia and highlight a spectrum of severity in this rare condition, which we propose has an autosomal dominant inheritance pattern. Complications such as upper respiratory obstruction secondary to laryngo-tracheal dysfunction need to be carefully monitored for in infancy because this is a preventable cause of mortality. The progression of a thoracic kyphoscoliosis in this condition is often relentless and resistant to surgical treatment. Other causes of morbidity include cervical instability, hearing loss, and functional impairments resulting from degenerative joint deformity. Intellectual outcome in all surviving cases has been normal. Final adult heights ranged from 107 to 135 cm.