Neurofibromatosis Type I (NF1)

Overview


Plain-Language Overview

Neurofibromatosis Type I (NF1) is a genetic disorder that primarily affects the nervous system and skin. It causes the growth of multiple benign tumors called neurofibromas on nerves throughout the body. People with NF1 often have distinctive café-au-lait spots, which are flat, pigmented skin patches. The condition can also lead to bone deformities and learning difficulties. NF1 is caused by changes in a gene that normally helps control cell growth, leading to abnormal tissue development.

Clinical Definition

Neurofibromatosis Type I (NF1) is an autosomal dominant disorder caused by mutations in the NF1 gene, which encodes the tumor suppressor protein neurofibromin. Loss of neurofibromin function results in increased RAS pathway activity, promoting uncontrolled cell proliferation and tumor formation. The disease is characterized by multiple cutaneous neurofibromas, plexiform neurofibromas, and café-au-lait macules. Other features include Lisch nodules (iris hamartomas), skeletal abnormalities such as sphenoid wing dysplasia, and increased risk of malignant peripheral nerve sheath tumors. NF1 has variable expressivity and can affect multiple organ systems, with significant morbidity related to tumor burden and neurological complications.

Clinical Presentation


Diagnostic Workup


Pathophysiology


Treatments


Prevention


Outcome & Complications


Differential Diagnoses


Medical Disclaimer: The content on this site is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. If you think you may be experiencing a medical emergency, call 911 or your local emergency number immediately. Always consult a licensed healthcare professional with questions about a medical condition.

Artificial Intelligence Use: Portions of this site’s content were generated or assisted by AI and reviewed by Erik Romano, MD; however, errors or omissions may occur.

Analytics Disclosure: If you allow analytics cookies, Doctogenic uses Google Analytics, Microsoft Application Insights, and Microsoft Clarity to understand site usage, diagnose issues, review heatmaps and session replay recordings, and improve the service on pages where those tools are enabled. Clarity is not enabled on account, purchase, billing, checkout, Stripe-related, or admin pages. You can change this choice through Cookie preferences.

USMLE® is a registered trademark of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). Doctogenic and Roscoe & Romano are not affiliated with, sponsored by, or endorsed by the USMLE, FSMB, or NBME. Neither FSMB nor NBME has reviewed or approved this content. "USMLE Step 1" and "USMLE Step 2 CK" are used only to identify the relevant examinations.