Disease Information for Neurofibromatosis: Definition

  • Neurofibromatosis Type 1 (NF-1); NF-1; Recklinghausen"s phakomatosis; Von Recklinghausen"s disease; Von Recklinghausen"s neurofibromatosis; neurofibroma, multiple; neurofibromatosis-pheochromocytoma-duodenal carcinoid syndrome; peripheral neurofibromatosis; segmental neurofibromatosis; Neurofibromatosis Type 1 also called von Recklinghausen"s Disease, is a rare genetic disorder characterized by the development of multiple noncancerous tumors of nerves and skin and areas of abnormally decreased or increased coloration (hypo- or hyperpigmentation) of the skin; Areas of abnormal pigmentation typically include pale tan cafe-au-lait spots

    on the skin of the trunk and other regions as well as freckling, particularly axillary and inguinal area; Such abnormalities of skin pigmentation are often evident by one year of age and tend to increase in size and number over time; At birth or early childhood, affected individuals may have relatively large benign tumors that consist of bundles of nerves (plexiform neurofibromas); Individuals with NF-1 may also develop benign tumor-like nodules of the colored regions of the eyes (Lisch nodules) or tumors of the optic nerves ; More rarely, affected individuals may develop certain malignant (cancerous) tumors; NF-1 may also be characterized by unusual largeness of the head (macrocephaly) and relatively short stature; Additional abnormalities may also be present, such as episodes of uncontrolled electrical activity in the brain (seizures); learning disabilities; speech difficulties; abnormally increased activity (hyperactivity); and skeletal malformations, including progressive curvature of the spine (scoliosis), bowing of the lower legs, and improper development of certain bones;

    Autosomal dominant inheritance, but often spontaneous mutation occurs; this is caused by mutations of a relatively large gene on the long arm (q) of chromosome 17 (17q11_2); The gene regulates the production of a protein known as neurofibromin, which is thought to function as a tumor suppressor; The name "Neurofibromatosis" is sometimes used generally to describe NF-1 as well as a second, distinct form of NF known as Neurofibromatosis Type II (NF-2); Also an autosomal dominant disorder, NF-2 is primarily characterized by benign tumors of both acoustic nerves, leading to progressive hearing loss; --------------[NORD