Neurofibromatosis-1 (NF-1) Flashcards
What is the inheritance pattern of NF-1?
90% AD
5% whole gene deletion
50% sporadic
What is the genetic mutation for NF-1?
NF-1 gene at chromosome 17q11.2
What are the diagnostic criteria for NF-1?
Two or more of the following:
1. Two or more neurofibromas or one plexiform neurofibroma
a) 6 or more CALM >5mm in prepubertal
b) 6 or more CALM >15mm postpubertal
2. Axillary or inguinal freckling (Crowe’s sign)
3. Optic nerve tumor
4. Two or more Lisch nodules (iris hamartoma)
5. Distinctive osseous lesion: sphenoid dysplasia or long-bone bowing with or
without psuedoarthrosis
5. First degree relative with NF-1
What are the associated medical findings for NF-1?
- Neurofibromas
- Optic nerve tumors
- Increased solid tumors and leukemia, CNS gliomas
- Sphenoid wing dysplasia
- Pseudoarthrosis
- Scoliosis
- HTN, increased cardiac defects (pulmonic stenosis, aortic coarctation, CAD)
What are the developmental outcomes for NF-1?
- Learning disabilities (40-60%)
- Impaired executive function
o inattention, impulsivity - Delayed speech and communication
- Learning problems tend to improve with age
What is the DDx for NF-1?
- Legius Syndrome (SPRED1 gene): CAL + axillary/inguinal freckling; no neurofibromas or ophthalmologic manifestations of NF1.
- McCune-Albright
Syndrome (polyostotic fibrous dysplasia). - Neurofibromatosis Type 2. Multiple autosomal dominant CAL macules without neurofibromas.
What are the recommendations for NF-1?
- Developmental assessment/school support
- MRI any suspected plexiform neurofibromas
- Low threshold for Brain MRI
- Manage scoliosis
- Routine BP checks
- Annual Peds Ophtho exams
What are the major clinical characteristics of NF-1?
- Multiple cafe au lait spots
- Axillary and/or inguinal freckling
- Neurofibromas
- Iris Lisch nodules
- Scoliosis
- Plexiform neurofibromas
- CNS gliomas
- Malignant peripheral nerve sheath tumors
