Genetics

Question 1

RB1 deletion

Answer 1

Retinoblastoma and

Question 2

Deletion of Ch 3p25.3

Answer 2

von Hippel-Lindau dx; retinal gngiomatosis

Question 3

Deletion of Ch 22q11.2

Answer 3

AT/RT- INI1/hSNF5, deletion is most common but occasionally caused by mutation

Question 4

Deletion of 9q21

Answer 4

p16 deletion, anaplastic meningioma

Question 5

NF1

Answer 5

von Recklinghausen’s disease. Neurofibromin 17q11.2 Autosomal dominant, with 100% penetrance. 50% of cases are sporadic. 10x more common than NF2. Neurofibromas (particularly plexiform), optic nerve gliomas, increased risk of CML and other malignancies

Question 6

BAF47

Answer 6

IHC marker for AT/RT (INI1 loss)

Question 7

AT/RT

Answer 7

Mutation or deletion of INI1 (detected by loss of BAF47 IHC positivity) or less frequently BRG1 mutation/deletion