Neurofibromatosis is an autosomal dominant genetic disorder. It encompasses a set of distinct genetic disorders that cause tumors to grow along types of nerves and, in addition, can affect the development of non-nervous tissues such as bones and skin. The tumors can grow anywhere on or in the body. Neurofibromatosis type I (formerly known as Von Recklinghausen disease after Friedrich Daniel von Recklinghausen) has an incidence is 1:3000. It is caused by mutations in the NF1 gene on chromosome 17. Most of these mutations seen are new spontaneous mutations.
More scientific background is here: http://tinyurl.com/8xdwf37