Understanding Neurofibromatosis: Symptoms and Underlying Causes

Understanding Neurofibromatosis: Symptoms and Causes

Neurofibromatosis is a hereditary condition characterized by tumor formation within the nervous system. The main types include neurofibromatosis type 1 (NF1), type 2 (NF2), and schwannomatosis. While often mild, its symptoms can sometimes lead to significant health issues. Here's an overview of common signs and the factors that cause them.

Manifestations
The typical symptoms include:

Skin nodules
Small bumps, known as neurofibromas, develop on or beneath the skin. These tumors can also form internally, and when nerve-related, may cause facial deformities.

As individuals age, neurofibromas may increase in number.

Cognitive challenges
Children with NF1 may face learning difficulties, such as trouble reading or doing math. They might also experience ADHD or speech delays.

Skin pigmentation
Light brown spots called cafe au lait spots are common. Presence of more than six spots often indicates NF1. These spots appear at birth or early childhood and fade with age.

Eye and skin features
Freckles in body folds and Lisch nodules in the iris are common findings. These are painless and benign.

Problems with hearing and balance are associated with NF2, caused by slow-growing tumors in the ear nerves. Symptoms include hearing loss, tinnitus, and balance issues.

Causes of Neurofibromatosis
The development of this condition stems from genetic mutations:

NF1 gene
Located on chromosome 17, this gene encodes neurofibromin, a protein that controls cell growth. Mutations reduce neurofibromin, leading to uncontrolled cell proliferation.

NF2 gene
This gene produces merlin, which inhibits tumor formation. Mutations cause loss of merlin, resulting in abnormal cell growth.

Schwannomatosis
Both NF1 and NF2 mutations can lead to schwannomatosis, characterized by nerve tumors, usually sparing the nerve pathways responsible for hearing.