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