Neurofibromatosis Flashcards
What is Neurofibromatosis
Genetic condition that causes benign neuromas to develop throughout the nervous system, causing neurological and structural problems
Types of neurofibromas
Neurofibromatosis Type 1 - more common
Neurofibromatosis Type 2
Neurofibromatosis type 1 gene
NF1 gene on chromosome 17
Codes for neurofibromin (tumour suppressor gene)
Inheritance of neurofibromatosis type 1
Autosomal dominant
Diagnostic criteria for neurofibromatosis type 1
At least 2 of 7 features for diagnosis
(CRABBING)
Cafe au lait spots - 6+ measuring 5+mm in children or 15mm in adults
Relative with NF1
Axillary or inguinal freckles
Bony dysplasia - bowing of a long bone or sphenoid wing dysplasia
Iris harmatomas 2+
Neurofibromas 2+
Glioma of the optic nerve
What is a iris harmatoma
Yellow brown spots on the iris
Investigations for neurofibromatosis
(No investigations are required for diagnosis)
Genetic testing
X-rays - bone pain and lesions
CT - for lesions
Management
Manage complications
Complications of neurofibromatosis
Migraines Epilepsy Renal artery stenosis - hypertension Learning disability - ADHD Scoliosis of spine Vision loss
Increased risk of cancer: e.g. breast
Malignant peripheral nerve sheath tumours
GI stromatolites tumour
Brain tumours
Leukaemia
Spinal cord tumours
Congenital absence of the greater wing of sphenoid - pulsatile proptosis
Neurofibromatosis type 2 gene
NF2 gene on chromosome 22 codes for a protein called merlin which is a tumour suppressor gene important in Schwann cells
Inheritance of neurofibromatosis type 2
Autosomal dominant
Neurofibromatosis type 2
Development of Schwannomas
What condition is neurofibromatosis type 2 associated with
Acoustic neuroma especially if bilateral
Triad for acoustic neuroma
Tinnitus
Hearing loss
Loss of balance
Complications of neurofibromatosis type 2
Schwannoma development in the brain or spinal cord
