Ch. 61-Neurofibromatosis + Tuberous Sclerosis Flashcards
(95 cards)
What is the inheritance pattern of most cancer syndromes?
AD
Inheritance pattern of NF? TS?
AD for both
What is the penetrance of NF-1? TS?
100% penetrant for both
What % NF-1 is de novo?
50%
Describe NF varaints 1-7
NF1
NF-2-acoustic schwanomma
NF-3: central and peripheral neurofibromas (MIXED)
NF-4: Vairant
NF-5: Segmental/Mosaic NF= CALMs/NFs affecting 1 or more dermatomes
NF-6: CALMs only, includes Legius syndrome
NF-7: late onset
Incidence NF-1
1 in 3000
What gene is mutated in NF-1? What does it code for?
NF1 gene—> Neurofibromin
What is the most common mutation in NF-1?
Mutation that results in truncated neurofibromin protein
Sometimes get a large microdeletion with more severe phenotype
Chromsomome of NF-1?
17q11.2
What is role of neurofibromin (1-what pathway 2-general role)
RAS-MAPK pathway that promotes cell survival and proliferation
Role played as tumor supressor (down regulates this pathway)
What drug can be used to block neurofibroma formaiton?
Imatinib (tyrosine kinase inhibitor)
-C-kit ligand is oversecreted by NF-/- (Loss of heterozygosity) schwaan cells, recruits mast cells (that are NF+/-) that secrete factors promoting neurofibroma genesis
Name 6 cutaneous findings in NF-1
CALMs (Need 6 or more, >5 or 15 mm)
Axillary./inguinal freckling
Neurofibromas (regular or plexiform)
Nevus anemicus
JXG
Name 3 ocular findings in NF-1
Lisch nodules (90%)
Choroidal nodules
Optic glioma (also under tumor section)
Neovascular glaucoma
Name 6 skeletal/MSK related findings in NF-1
Scoliosis
Spina bifida
Long bone cortex dysplasia (tibia)
Psuedoarthrosis
Osteopenia and osteoporosis
Short stature
Pectus deformity
Name 4 tumors in NF-1? (There are more)
Optic glioma
Malignant peripheral nerve sheath tumor
Breast cancer-5 fold risk
Pheo
Juvenile myelomonocytic leulemia
Non optic glioma CNS tumors
Rhabdomyosarcoma
Duodeanl carcinoid
Somatostatinoma
Parathyroid adenoma
GISTs
Name 3 cranial findings in NF-1
Sphenoid wing dysplasia
Macrocephaly
Hypertelorism
What are some neurologic related findings in NF-1
Learning difficulties
Unidentified bright objects on MRI
Seizures
Intellecutal disability
What is the main CV findings in NF-1? Name 3 others
Essential hypertension
Pulmonic stenosis, RAS, cerebrovascular anomalies
What is the diagnostic criteria for NF-1?
Need 2 of the following:
CAFESPOT
C: CALMS (6 or more, 5 mm prepubertal or 15 mm post)
A: Axillary/inguinal freckling
F: Fibroma-2 or more neurofibromas, or 1 plexiform
E: Eyes-lisch nodules 2 or more
S: Skeletal: Anterolateral bowing tibia or psueodoarthrosis long bone, or sphenoid dysplasia
P: Parental with NF
OT: Optic tumor (optic glioma
What is the ddx for multiple CALMS? Name 10
- NF-2
- Mosaic NF (NF-5)
- Multiple familial cafe au lait (NF-6)
- Legius (NF-1 like)
- McCune Albright Syndrome
- Constitutional Mismatch Repair Deficiency (CMMRD)
- Noonan/LEOPARD (Noonan syndrome with multiple lentigines)
- Ring Chromosome Syndrome
- Cowdens
- Banayan-Riley-Ruvalcaba syndrome
Others with weaker association
- NAME syndrome (Carney complex, also LAMB)
- Ataxia Telengiectasia
- Epidermal nevus syndrome (extensive epidermal and sebaceous nevi)
- Turner
- Russel Silver
- Fanconis anemia
- MEN1/2B
- BLoom
- Watson syndrome
- Westerhof syndrome
- Hunter disease
Others that Bolognia mentions:
-Tuberous Sclerosis
-Piebaldism
-Familial progressive hyper and hypopigmentation
-Mukamel Syndrome
-Partial unilateral lentiginosis
-Gastrocutaneous syndrome
-Tay syndrome
-Tricho-hepato-enteric syndrome
-Johnson McMillin syndrome
What are the features of Legius?
Multiple CALMs, axillary freckling
No other NF-1 stigmata (No lisch, no optic gliomas, no NFs)
Macrocephaly, lipoma, learning disability, hypopigmented macules
What are the features of McCune Albright? What gene?
GNAS1
CALMs-but segmental, larger, less uniform
Precocious puberty
Other endocrinopathies
Polyostotic fibrous dysplasia
What are the features of CMMR deficiency? What genes?
MSH2, MSH6, PMS2, MLH1
Multiple CALMs
Cancers: Medulloblastoma, lymphoma, glioblastoma, colonic polyps
What are the features of segmental NF (NF-5 formerly)
Neurofibromas alone or CALMS +- axillary freckling in block like pattern
Post zygotic NF-1 mutation in some which may involve the gonads