NF 1 &2

Question 1

Genotype of NF1

Answer 1

• Heterozygous mutation in the neurofibromin gene on chromosome 17 q11
• Autosomal dominant disorder

Question 2

Genotype of NF2

Answer 2

• Mutation in the gene encoding merlin on chromosome 22 q12

- Also known as Central Neurofibromatosis

Question 3

NF Type 1 Phenotype

Answer 3

• Cafe-au-lait spots, Lisch nodules in the eye, and fibromatous tumors of the skin
• Peripheral neurofibromatosis

Question 4

Dystrophic scoliosis

Answer 4

• Less common
• Short segment, sharply angulated curve
• Serve the dystrophic changes the greater the chance the curve will deteriorate

Question 5

Most common type of NF

Answer 5

NF 1 “peripheral”

Question 6

NF Type 2 Phenotype

Answer 6

• Hallmark finding in NF2 is slow-growing tumors on the CN VIII
• Acoustic branch helps people hear by transmitting sound sensation to the brain and the vestibular branch helps people maintain their balance
• Vestibular schwannomas- characteristic tumors
• Schwannomas may occur along any nerve in the body
• Cataracts
• Rarely have cafe-au-lait spots

Question 7

NF 2 Facts

Answer 7

• Type II is a rare disorder affecting 1 in 25,000

- 50% of affected people inherit the disorder

Question 8

NF 2 at risk for developing other types of nervous system tumors including

Answer 8

Ependymomas and gliomas (two tumor types that grow in the spinal cord) and meningiomas (tumors that grow along the protective layers surrounding the brain and spinal cord)

Question 9

First presenting symptom

NF 2

Answer 9

• Hearing loss or tinnitus

- Less often disturbances in balance, visual impairment

Question 10

NF 2 life expectancy

Answer 10

• Varies greatly among individuals

- An earlier age of onset and the presence of meningiomas are associated with greater mortality risk