<prompt> A 12 year old girl child presents with head ache, unsteadiness and poor hearing which has worsened over the past 5 years. His father has a history of brain surgery and he is deaf since his 35 years. Most likely diagnosis in the childOptic gliomaTuberous sclerosisNeurofibromatosis 2Late onset congenital deafness  <response>: Answer: c Neurofibromatosis 2 HARRISON 19TH ED, P-604NEUROFIBROMATOSISType 1 Von Recklinghausen diseaseType 2 Acoustic neurofibromatosis Most common phakomatosis 50 have family history NF1 gene in Chr 17 that encodes Neurofibromin Cafe-au-lait spots Lisch nodules Iris hamartoma Cutaneous, subcutaneous and plexiform premalignant neurofibromas Pseudoarthrosis of the tibiaIncreased risk of Optic nerve glioma most common CNS tumor Meningioma, Schwannoma, Astrocytoma Pheochromocytoma NF 2 gene in Chr 22 that encodes Merlin Cafe-au-lait spots Lisch nodules not seenIncreased risk of Bilateral acoustic schwannomas most common Meningioma, Astrocytoma, Ependymoma Nodular ingrowth of Schwann cells into the spinal cord Schwannosis Proliferation of meningeal cells and blood vessels that grows into the brainMeningioangiomatosis Microscopic collections of glial cells at abnormal locations glial hamartia often in the cerebral cortexNeurofibromatosis type 2 NF2Characterized by the development of bilateral vestibular schwannomas acoustic neuromas in 90 that lead to deafness, tinnitus, or vertigo.Some patients with NF2 also develop meningiomas, spinal schwannomas, peripheral nerve neurofibromas, and cafe au lait macules.Endocrine abnormalities are not found in NF2 and are associated solely with NF1Malignant change may occur in NF1 neurofibromas but is rare in NF2 schwannomas 