To reduce the impact of the constitutional variability and to address the issue of the recurrence of variants in the NF1 gene, in the present study we analyzed the genotype/phenotype correlations of patients bearing the same constitutional pathogenic variant, by selecting from our large record of 1007 patients 34 NF1 recurrent variants (those carried by at least two unrelated patients) and by correlating them with the Neurofibromatosis type I phenotype, in particular with the onset of complications and cancers. This evidence concerns the gene NF1 and cancer.