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Neurofibromatosis

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Neurofibromatosis, von Recklinghausen Disease

  • Epidemiology
  1. Autosomal Dominant
    1. Chromosome region 17q11.2
    2. Parent with NF has 50% of transmission per birth
  2. Incidence
    1. NF-1: 1 in 4000
    2. NF-2: 1 in 50,000
  • Pathophysiology
  1. Disorder of neural crest differentiation
  • Diagnostic Criteria
  • NF-1 (any 2 of below present)
  1. Cafe-Au-Lait Spots (6 or more in 100% of cases)
    1. Pre-Puberty: >5 mm greatest diameter
    2. Post-Puberty: >15 mm greatest diameter
  2. Axillary or inguinal Freckles (2-3 mm diameter)
  3. Iris Lisch Nodules (2 or more)
    1. Hamartomas on iris (Slit Lamp exam)
    2. Present in half by kindergarten, 100% by age 21 years
  4. Optic Glioma (Optic Nerve benign tumor)
    1. Pupil dilates on response to bright light
  5. Neurofibromas (2 or more)
    1. Small, Rubbery, purple skin lesions
  6. Bone abnormalities (one of associated conditions)
    1. Scoliosis (most common)
    2. Sphenoid dysplasia
    3. Long bone cortical thinning
  7. First degree relative with NF-1
  • Diagnostic Criteria
  • NF-2 (one of the following)
  1. Bilateral Cranial Nerve 8 Acoustic Neuromas
  2. First degree relative with NF-2 and one criteria below:
    1. Unilateral Acoustic Neuroma
    2. Neurofibroma (much less common in NF-2)
    3. Meningioma
    4. Glioma
    5. Schwannoma
    6. Posterior subcapsular lenticular opacity
  • Associated Conditions
  1. NF-1
    1. Intracranial low grade gliomas and hamartomas
    2. Learning disabilities (e.g. ADHD)
    3. Speech abnormalities
    4. Seizure Disorder
    5. Macrocephaly
    6. Hydrocephalus (rare)
    7. Cerebrovascular Disease (Moyamoya Disease)
    8. Hypertension
      1. Associated with Renal Artery Stenosis
      2. NF-1 also associated with Pheochromocytoma
    9. Precocious Puberty
    10. Malignancies (e.g. Leukemia, Wilms' Tumor)
    11. CNS tumors (e.g. meningiomas, astrocytomas)
  2. NF-2
    1. CNS tumors (e.g. Schwann cell, glioma, meningioma)
  • Monitoring
  1. Detailed history and physical periodically
  2. Pediatric Ophthalmology annually
  • References
  1. Behrman (2000) Nelson Textbook of Pediatrics, p. 1835
  2. Debella (2000) Pediatrics 105:608-14 [PubMed]
  3. Lynch (2002) Neurol Clin 20(3):841-65 [PubMed]