Neurofibromatosis

Question 1

What is Neurofibromatosis?

Answer 1

Neurofibromatosis is a genetic disorder of the nervous system. It mainly affects how nerve cells form and grow. It causes tumors to grow on nerves.

Question 2

What are the signs and symptoms of neurofibromatosis?

Answer 2

> Pain
Compromised vision- optic disc pallor and iris Lisch nodes
Neurological deficits
Skin- cafe au lait spots, axilla freckles, cutaneous juvenile xanthogranulomas, neurofibromas
CNS- hydrocephalus, tumours, cerebellar problem
PNS- Palpable masses
Skeletal- tibial dysplasia, pectus excavatum, genu valgum/ varum, ankle valgus
Vascular- abdo pain, neuro problem
Autism spectrum disorder

Question 3

What are the risk factors of neurofibromatosis?

Answer 3

> Genetics- parental

> Severe Crush trauma

Question 4

What is the epidemiology of neurofibromatosis?

Answer 4

For all populations studied, the overall frequency of NF1 is about 1 in 2500-3000, with one third of all cases and half of new presenting cases representing new mutations and the remainder being inherited from an affected parent.

Question 5

What investigations would you do for neurofibromatosis?

Answer 5

> MRI/ CT- shows evidence of tumours or hydrocephalus
PET
Biopsy- tumours
Genetic testing for NF1 mutation

Question 6

What are the types of Neurofibromatosis?

Answer 6

The three types are neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis

Question 7

Which type is most common?

Answer 7

Neurofibromatosis type 1

Question 8

What are the signs and symptoms of NF2?

Answer 8

Bilateral vestibular schwannomas, intracranial meningiomas and/or ependymomas, spinal glioma, paraspinal schwannomas, cutaneous schwannomas, posterior subcapsular cataracts, pigmentary retinopathy, absence of typical café au lait spots

Question 9

What would you find on investigation of NF2?

Answer 9

Identification of a mutation at the NF2 locus in chromosome band 22q11