Neurofibromatosis and hypertelorism.

Hypertelorism was observed in eight of 34 patients with neurofibromatosis. This diagnosis was made by measuring the intercanthal distance and calculating the interpupillary distance from it. The bones of the base of the skull and of the face are mesenchymal structures of neural crest origin. Skull dysplasias, in which hypertelorism can be included, fit well into the neurocristopathy concept of neurofibromatosis. Hypertelorism seems to herald a severe expression of neurofibromatosis, eg, with brain involvement, and would therefore be an indication for doing a computed tomographic scan. The high prevalence of hypertelorism in our group of patients (24%) makes its direct association with neurofibromatosis highly feasible. Its ease of clinical recognition and its presence at birth would make it a valuable early diagnostic criterion.