Neurofibromatosis

Neurofibromatosis (NF)By Angela M.

OverviewDiscovered by Friedrich Daniel von Recklinghausen in 1882Genetic neurological disorder that affects cell growth in nerve tissueOccurs throughout the world and affects men and women of all races and ethnic groups equally, but is more prevalent in cystic fibrosis, Duchenne muscular dystrophy and Huntingtons disease combined3 different types: Type 1, Type 2, and Schwannomatosis

Type 1Also called von Recklinghausen NeurofibromatosisTransmitted on chromosome 17Caused by a mutation or deletion (very rarely) of the NF1 geneOccurs in late childhoodOccurs in 1 to 3,000 births worldwide

Type 2Transmitted on chromosome 22Caused by mutation or deletion (very rarely) of the NF2 geneOccurs in late teens / early 20sOccurs in 1 to 25,000 people worldwide

SchwannomatosisRare form in which multiple benign tumors form in peripheral nerve fiber cellsOccurs in 1 to 40,000 people worldwide

How you get itInherited as an autosomal dominant trait, but can also result from spontaneous genetic mutationsParent with the disorder has a 50% chance of passing it on to his/her childrenParent can only pass his/her type of NF to the child

50% Nn affected50% nn - normalNnnNnnnnNnnn

Signs and SymptomsType 1: Multiple skin lesions that appear during infancyBenign tumors (may or may not be painful) may develop on skin (cutaneous), under skin(subcutaneous), and in connective nerve tissues (schwannomas) in adolescence; in 2-5% of cases tumors become malignant Curvature of the spine (scoliosis)DizzinessEnlargement and deformity of bones (may cause chronic pain)Hearing lossLearning disabilitiesTumors of optic nerves (optic gliomas) may cause blurry vision, vision loss, and Lisch nodules ( type of benign tumor) on iris

Signs and Symptoms (Ctn.)Type 2:Tumors frequently develop on 8th cranial nerve causing symptoms such as:DizzinessRinging in earsLoss of balanceSignificant hearing lossSchwannomatosis:Chronic pain in any part of the body

Treatment / PreventionNo cureCannot be preventedSurgeryCan remove painful cutaneous and subcutaneous tumors and those that occur on visible areas of the bodyMay also remove schwannomas and nerve tissue tumors that cause pain, sensory loss, and loss of functionRadiationShrink tumors

PrognosisType 1:Most have normal life expectancy, but severe cases may reduce life expectancy by up to 15 yearsType 2:Depends on age of onset and number and location of tumorsPrompt diagnosis and treatment may improve life expectancy up to more than 15 years following diagnosisSchwannomatosis: Too rare to be determined