Neurofibromatosis type 1 is a relatively common tumor predisposition syndrome clinically evident through caf\u00e9 au lait spots, neurofibromas on and under the skin, and freckles in the armpits and groin area. In addition, NF1 is characterized by iris hamartomas, characteristic bone changes, scoliosis, macrocephaly, dwarfism, and learning disabilities. Occasionally, tumors may also develop in the vicinity of cranial nerves or the spinal cord and, in principle, around every peripheral nerve. NF1 is normally diagnosed during childhood.<\/p>\n<\/div>
Synonyms:<\/p>\n<\/div><\/div><\/div>
NF1, Recklinghausen\u2019s disease<\/p>\n<\/div><\/div><\/div><\/div>
Gene:<\/p>\n<\/div><\/div><\/div>
NF1<\/em> tumor suppressor gene<\/p>\n<\/div><\/div><\/div><\/div> Gene \u00adproducts:<\/p>\n<\/div><\/div><\/div> Neurofibromin<\/p>\n<\/div><\/div><\/div><\/div> Function:<\/p>\n<\/div><\/div><\/div> The regulation of cell growth and cell differentiation in nerve cells and myelin sheaths. Tumors develop due to the down-regulation of the RAS signal transduction cascade.<\/p>\n<\/div><\/div><\/div><\/div> Pattern of inheritance:<\/p>\n<\/div><\/div><\/div> Autosomal dominant (50%), de novo<\/em> (50%; intron mutation, exon deletion, missense mutation, insertion, point mutation, stop mutations), rarely mosaic or segmentally limited postzygotic form of NF1<\/p>\n<\/div><\/div><\/div><\/div> Prevalence:<\/p>\n<\/div><\/div><\/div> 1:3.000<\/p>\n<\/div><\/div><\/div><\/div> Genotype-phenotype correlation:<\/p>\n<\/div><\/div><\/div> Low, with very high expression variability<\/p>\n<\/div><\/div><\/div><\/div> Penetrance:<\/p>\n<\/div><\/div><\/div> Almost 100% in adulthood<\/p>\n<\/div><\/div><\/div><\/div><\/div><\/div>