Neurofibromatosis type 1 (NF1)

• A genetic disorder characterized by:
  • a number of remarkable skin findings including multiple café au lait (coffee with milk) spots, which increase in number and size with age (97% of people have 6 or more spots by age 20)
  • multiple benign tumors called neurofibromas on the skin
  • plexiform neurofibromas (thick and misshapen nerves due to the abnormal growth of cells and tissues that cover the nerve), which usually appear in the second decade of life
  • and freckles in the armpit and groin.
• Also called von Recklinghausen disease

Complications:

• In NF1 there is an increased risk of scoliosis, optic gliomas (benign tumors on the optic nerve), epilepsy, and learning disability. The risk of malignant degeneration of neurofibromas is below 5 percent.

Cause:

• NF1 is inherited in an autosomal dominant manner and is due to mutation of the NF1 gene (in chromosome band 17q11) that encodes a protein called neurofibromin.
  • Half of cases are due to new mutations in the NF1 gene. Prenatal testing is available.