The criteria of the National Institutes of Health (NIH) for NF1 diagnosis established in 1987 were revised in 2021, to include six or more café-au-lait macules (CALMs, ≥5 mm in prepubertal individuals); axillary or inguinal freckling; two or more neurofibromas or one plexiform neurofibroma (PN); optic pathway glioma; Lisch nodules or choroidal abnormalities; a distinctive osseous lesion (e.g., sphenoid dysplasia, anterolateral bowing of the tibia, or pseudarthrosis of a long bone); and a heterozygous pathogenic NF1 variant [8,9,10]. This evidence concerns the gene NF1 and optic pathway glioma.