Background: Kyphoscoliosis is a complication of some bone dysplasias, including cleidocranial dysplasia.
Objectives: We report a distinct disorder with defective ossification of the ischial rami, severe kyphoscoliosis and normal clavicles. Early recognition of this syndrome allows prevention of complications.
Materials and methods: All patient cases (aged 1 day to 33 years) were selected according to the above criteria, with special attention to radiological findings, family history and follow-up (5-30 years).
Results: In all eight patients, we observed the following: (a) Severe thoracic scoliosis of early onset and rapid progression, leading to rotatory dislocation. Spinal cord compression occurred in four cases with respiratory problems related to chest deformity. (b) Bilateral and symmetrical incomplete ossification of the ischial rami. (c) Peculiar facies with retrognathia. (d) Normal clavicles. Three patients were from the same family (grandmother, mother and daughter).
Conclusion: Ischio-vertebral dysplasia seems to represent a true entity, with radiological and genetic findings that make it distinct from cleidocranial dysostosis. The association of kyphoscoliosis and these pelvic abnormalities is specific for this condition. Neurological and respiratory complications can be avoided if the condition is recognised early and early treatment is instituted.