[Neurofibromatosis I: a clinical series and genetic correlations].

Type 1 neurofibromatosis represents 90% of all forms of neurofibromatosis. It is a disease with an incidence of 1:3000 neonates with a dominant autosomic form of transmission, but 50% of all cases are sporadic owing to new mutations. Diagnosis is mainly clinical and requires at least of the following signs: CAL, neurofibromas, glioma of the optic nerve, axillary lentigo, Lisch's nodules, bone lesions and the presence of the disease in at least one first-degree relation. These criteria may also be applied in children under 6 years old as is confirmed by the clinical series of 5 cases referred to our attention. The deletion of the long arm of chromosome 17 in the zone proximal to the centromere containing the gene of type 1 neurofibromatosis was observed in one case. The phenotype of this subject was correlated to another 5 cases reported in the literature.