Heritable Disorders: Neurofibromatosis

Question 1

Neurofibromatosis TI eponym

Answer 1

(Type I; von Recklinghausen’s Disease)

Question 2

Neurofibromatosis TI diagnostic criteria

Answer 2

1. more than 5 café-au-lait patches >1.5 cm in an adult or more than 5 café-au-lait macules >0.5 cm
   in a child <5 yr
2. axillary or inguinal freckling
3. iris hamartomas (Lisch nodules)
4. optic gliomas
5. neurobromas
6. distinctive bony lesion (sphenoid wing dysplasia or thinning of long bone cortex)
7. first degree relative with neurobromatosis Type 1

Question 3

Neurofibromatosis TI how many criteria needed for Dx?

Answer 3

2 or more of them

Question 4

Neurofibromatosis TI associated Pathologies

Answer 4

with pheochromocytoma, astrocytoma, bilateral acoustic neuromas, bone cysts, scoliosis, precocious puberty, developmental delay, and renal artery stenosis

Question 5

Neurofibromatosis TI comparison to type II

Answer 5

skin lesions less prominent in neurofibromatosis Type II

Question 6

Neurofibromatosis TI Pathophysiology

Answer 6

autosomal dominant disorder with excessive and abnormal proliferation of neural crest elements
(Schwann cells, melanocytes), high incidence of spontaneous mutation

Question 7

Neurofibromatosis gene involved

Answer 7

linked to absence of Neurofibromin (a tumour suppressor gene)

Question 8

Neurofibromatosis TI Epidemiology

Answer 8

incidence 1:3000

Question 9

Neurofibromatosis TI Investigations

Answer 9

Wood’s lamp to detect café-au-lait macules in patients with pale skin

Question 10

Neurofibromatosis TI Management, references

Answer 10

refer to orthopedics, ophthalmology, plastics, and psychology

Question 11

Neurofibromatosis TI follow-up

Answer 11

annually for brain tumours (e.g. astrocytoma)

Question 12

Neurofibromatosis TI lesions

Answer 12

excise suspicious or painful lesions