From OMIM
Neurofibromatosis type I (NF1) is an autosomal dominant disorder characterized by cafe-au-lait spots, Lisch nodules, and fibromatous tumors of the skin. Individuals with the disorder have increased susceptibility to the development of benign and malignant tumors. NF1 is sometimes referred to as 'peripheral neurofibromatosis.' The worldwide incidence of NF1 is 1 in 2,500 to 1 in 3,000 individuals (reviews by Shen et al., 1996 and Williams et al., 2009). Type II neurofibromatosis (NF2; 101000) is a genetically distinct disorder caused by mutation in the gene encoding merlin (NF2; 607379) on chromosome 22q12. NF2, sometimes known as 'central neurofibromatosis,' is characterized by bilateral acoustic neuroma and meningioma, but few skin lesions or neurofibromas (Rouleau et al., 1993). Some patients with homozygous or compound heterozygous mutations in mismatch repair genes (see, e.g., MLH1; 120436 and MSH2; 609309) have a phenotype characterized by early onset malignancies and mild features of NF1, especially cafe-au-lait spots; this is known as the mismatch repair cancer syndrome (see MMRCS1, 276300), sometimes referred to as brain tumor-polyposis syndrome-1 or Turcot syndrome. These patients typically do not have germline mutations in the NF1 gene, although a study by Wang et al. (2003) suggested that biallelic mutations in mismatch repair genes may cause somatic mutations in the NF1 gene, perhaps resulting in isolated features resembling NF1. See also Legius syndrome (611431), a genetically distinct disorder with a similar phenotype to NF1.  http://www.omim.org/entry/162200

From MedlinePlus Genetics
Neurofibromatosis type 1 is a condition characterized by changes in skin coloring (pigmentation) and the growth of tumors along nerves in the skin, brain, and other parts of the body. The signs and symptoms of this condition vary widely among affected people.

Beginning in early childhood, almost all people with neurofibromatosis type 1 have multiple café-au-lait spots, which are flat patches on the skin that are darker than the surrounding area. These spots increase in size and number as the individual grows older. Freckles in the underarms and groin typically develop later in childhood.

Most adults with neurofibromatosis type 1 develop neurofibromas, which are noncancerous (benign) tumors that are usually located on or just under the skin. These tumors may also occur in nerves near the spinal cord or along nerves elsewhere in the body. Some people with neurofibromatosis type 1 develop cancerous tumors that grow along nerves. These tumors, which usually develop in adolescence or adulthood, are called malignant peripheral nerve sheath tumors. People with neurofibromatosis type 1 also have an increased risk of developing other cancers, including brain tumors and cancer of blood-forming tissue (leukemia).

During childhood, benign growths called Lisch nodules often appear in the colored part of the eye (the iris). Lisch nodules do not interfere with vision. Some affected individuals also develop tumors that grow along the nerve leading from the eye to the brain (the optic nerve). These tumors, which are called optic gliomas, may lead to reduced vision or total vision loss. In some cases, optic gliomas have no effect on vision.

Additional signs and symptoms of neurofibromatosis type 1 vary, but they can include high blood pressure (hypertension), short stature, an unusually large head (macrocephaly), and skeletal abnormalities such as an abnormal curvature of the spine (scoliosis). Although most people with neurofibromatosis type 1 have normal intelligence, learning disabilities and attention-deficit/hyperactivity disorder (ADHD) occur frequently in affected individuals.  https://medlineplus.gov/genetics/condition/neurofibromatosis-type-1