Medicalpediaabout 4 years ago

Neurofibromatosis type 1

Hundreds of nerve tumors that form soft bumps on/under the skin! This very specific clinical finding is associated with neurofibromatosis type 1 (NF1), also called von Recklinghausen's disease, a rare genetic disorder characterized by the development of multiple noncancerous (benign) tumors of nerves and skin (neurofibromas) and areas of abnormally decreased or increased coloration (hypo- or hyperpigmentation) of the skin. It is one of the most common genetic disorders and affects 1 in 3,500. Adults develop neurofibromas, which are noncancerous (benign) peripheral nerve sheath tumors that are usually located on or just under the skin. Many have also multiple café-au-lait spots, which are flat patches on the skin that are darker than the surrounding area. NF-1 is caused by a mutation of a gene on the long arm of chromosome 17 which encodes a protein known as neurofibromin, which is a negative regulator of the Ras oncogene signal transduction pathway. When Ras isn’t regulated, it is overexpressed. These are a family of proteins that are involved in cellular signal transduction. A cascade effect occurs when ras is “switched on” by incoming signals, leading to activation of other proteins, which, in turn, activate genes responsible for cell growth and differentiation, hence leading to neurofibromas. Due to their benign nature, neurofibromas should be surgically excised only when symptomatic. Credit: @medicaltalks