Novel spinal dysplasia in two generations

We report on a father and son with a previously undescribed skeletal abnormality and severe short stature. Antenatal sonographic evaluation of the propositus (son), obtained due to maternal pre-eclampsia, suggested an abnormal spine. At birth, no congenital anomalies were noted and transition to extra-uterine life was smooth. Radiographs performed five days after birth showed spina bifida, hemivertebrae in the mid-thoracic region, and widened lumbar interpedicular distances. MRI of the lower thoracic and lumbar vertebrae documented crescent-shaped appearance of the affected vertebrae and abnormally narrow A-P diameter of the vertebral bodies. Intervertebral discs were small, and the posterior elements, as well as the spinous processes of the affected vertebrae, were markedly hypoplastic. However, there was no narrowness of the spinal canal, and the limbs were unaffected. CT scan with three-dimensional reformatting of the thoracic and lumbar vertebrae documented unusual sagittal clefting of all of the vertebral bodies, which has previously been undescribed. The father had severe kyphoscoliosis and a height of 131.6 cm (-7.5 S.D.). Radiographically, he was found to have multiple segmentation anomalies and diminished A-P diameter of his affected vertebral bodies. The multiple vertebral anomalies are the probable cause for the father's severe kyphoscoliosis. The pattern of inheritance suggests that an autosomal dominant gene is responsible for this condition and that the father represents a de novo mutation. These radiographic abnormalities have not been described previously and represent a new form of vertebral spinal dysplasia.