Somatic mosaicism for deletion of the entire NF1 gene identified by FISH

Hum Genet. 1997 Feb;99(2):209-13. doi: 10.1007/s004390050341.


We report a young child with a large congenital cervical plexiform neurofibroma and multiple café-aul-ait spots in a generalized distribution who has mosaicism for complete deletion of the NF1 gene. The deletion was demonstrated with intragenic cosmid probes as well as YACs spanning a 700-kb contig including NF1, by two-color FISH with an NF1 and a control probe. Using different intragenic probes, deletion was found in 77-84% of cultured peripheral blood lymphocytes but not in cultured skin fibroblasts. Neither parent has signs of neurofibromatosis type 1 (NF1) or a gene deletion. This is the first report of mosaicism for complete deletion of the NF1 gene. The child did not have typical NF1 or display segmental features of NF1.

Publication types

  • Case Reports
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cells, Cultured
  • Chromosomes, Artificial, Yeast
  • Cosmids
  • Female
  • Gene Deletion*
  • Head and Neck Neoplasms / genetics*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant
  • Mosaicism*
  • Neurofibroma / genetics*
  • Neurofibromin 1
  • Proteins / genetics*


  • Neurofibromin 1
  • Proteins