Neurofibromatosis

Neurofibromatosis (NF) a common genetic disorder with an autosomal dominant pattern of inheritance with variable penetrance. NF is a complex disease with many different systemic manifestations and complications. Based on symptoms and the region of chromosomal abnormality, NF has been classified into two types: neurofibromatosis I (NF 1) and neurofibromatosis II (NF 2). NF 1, or von Recklinghausen's disease, has been localized to the long arm of chromosome 17 and occurs in nearly one in 3000 live births (1,2). Because NF 1 has many different manifestations, the National Institutes of Health (NIH) developed a standardized method to diagnose NF 1, which includes two of the following criteria: six or more café-au-lait spots; two or more neurofibromas or one plexiform neurofibroma; axillary or inguinal freckling; optic gliomas; osseous lesions; lesions of the iris known as Lisch's nodules; or a first-degree relative with NF 1 (3). In contrast, NF 2 has been localized to the long arm of chromosome 22 and has a much lower incidence of only one in 55,000 live births (4). It has been defined as either bilateral acoustic neuromas visualized with appropriate imaging or a first-degree relative with NF 2, in addition to either a unilateral eighth nerve palsy or two other lesions: neurofibroma, meningioma, glioma, schwannoma, or juvenile posterior subcapsular lenticular opacities (3). Despite the autosomal dominant pattern of inheritance, it is important to note that nearly 50% of all cases of NF 1 and a greater proportion of NF 2 cases are sporadic mutations (2). NF is a progressive, systemic disease that can affect many different areas of the body. Depending on the location, size, and growth of lesions, patients may require multiple trips to the operating room, which may vary from simple excision of cutaneous lesions to aneurysm repair to large resections of malignant peripheral nerve sheath tumors (MPNST).