Spondylometaphyseal dysplasia with cone-rod dystrophy.

PURPOSE

To report on the clinical ophthalmologic and radiographic findings in spondylometaphyseal dysplasia with cone-rod dystrophy.

BACKGROUND

The spondylometaphyseal dysplasias are a rare and heterogeneous group of disorders characterized by skeletal abnormalities of the spine and the metaphyses of long bones. In rare instances, spondylometaphyseal dysplasia can occur concomitantly with ocular abnormalities including a retinal degeneration of the cone-rod dystrophy type.

METHODS

Retrospective review of affected twin females with serial radiographic imaging, comprehensive ophthalmologic examination, fundus photography, and electroretinography.

RESULTS

The major radiographic findings involved bony abnormalities of the spine, metaphyses of the long bones and a distinctive shape to the bony pelvis. Both twins had a fine nystagmus that was present by 10 months of age. Dilated ocular fundus examination revealed similar appearing bilateral, large, excavated, well-circumscribed oval areas of chorioretinal atrophy occupying the macula between the aracades. Electroretinography showed a significant reduction in the photopic responses and slight reduction in the scotopic component of the waveforms consistent with cone-rod dystrophy.

CONCLUSIONS

Spondylometaphyseal dysplasia with cone-rod dystrophy is a rare congenital disorder of unknown inheritance pattern and pathophysiolgy. The ocular manifestations appear to stabilize in early adolescence whereas the skeletal abnormalities are progressive with age.