Neurofibromatosis
Neurofibromatosis Type 1 (NF1)
This is an autosomal dominant disorder caused by mutations in the NF1 tumor suppressor gene located on chromosome 17. It presents with several characteristic features:
- Cutaneous neurofibromas - benign neoplasms derived from neural crest cells that appear as soft, skin-colored growths
- Café-au-lait spots - hyperpigmented flat light brown patches (typically 6+ spots >5mm in prepubertal children or >15mm in postpubertal individuals)
- Axillary or inguinal freckling - small pigmented spots in the armpits or groin area
- Lisch nodules - pigmented iris hamartomas visible on eye examination
- Optic gliomas - benign tumors of the optic nerve that can affect vision
- Pheochromocytoma - rare catecholamine-secreting tumors (occurs in <5% of NF1 patients)