Prevalence, Clinical Characteristics, Progression, and Management of Neurofibromatosis Type 1 in Egypt (NF1-Egy)

Neurofibromatosis type 1 (NF1), a genetic disorder, results from NF1 gene mutations with nearly complete penetrance (1). NF1 is considered common as a rare disease; it has a birth incidence of approximately one every 3000 and a prevalence of one case every 3000-6000 individuals. Patients with NF1 present lifelong phenotypic variabilities, including those mentioned in the National Institutes of Health (NIH) diagnostic criteria: multiple cafe-au-lait macules, freckling, Lisch nodules, cutaneous neurofibromas, plexiform neurofibromas (PNs), optic pathway gliomas (OPG), and osseous lesions (1). Regarding PNs, they are present in about 30-50% of NF1 patients with deeper growth along internal nerve plexus cranial or large peripheral nerve sheaths, compared to cutaneous neurofibromas. NF1 clinical expression is unpredictable, age-related, and varies among patients; additionally, as a tumor predisposition disorder, it is associated with neoplastic complications that impair health-related quality of life (QoL). Thus, it is essential to gather data about the natural history of the disease to understand its burden on patients with NF1 and those who develop PN. Besides that, NF1 prevalence and patients' clinical characteristics are not well recognized in Egypt, and full surgical resection of PN is often challenging due to its invasive nature, location, and size. Accordingly, this is a disease registry to collect data about patients with NF1, both pediatrics and adults. And to understand the natural history of this disorder in Egypt over the past 14 years in real-world settings. For patients with NF1, with or without PNs, we aim to understand their treatment patterns and explore clinical and nonclinical factors influencing targeted outcomes.