genetics

Question 1

2 yo, bumps into things on rt side, whitish hue in rt pupil and strabimus, palpation of the eye causes pain —> multi focal tumor composed of cuboidal to columnar cells around the central lumen. Which chromosomal abnormality is likely present? what is the tumor?

Answer 1

chrom 13– retinoblastoma

Question 2

what is the most common malignant eye tumor of childhood?

Answer 2

retinablastoma

Question 3

familial retinablastoma is usually… unlike sporadic retinoblastoma which is usually…

Answer 3

familial: bilateral or multifocal
sporadic: unilatoral/unifocal (bc mutations must occur in both chrom 13 of somatic cell)

Question 4

retinablastoma is generally caused by mutation of what tumor suppressor gene? on which chrom?

Answer 4

RB on chrom 13 (13q14)

Question 5

Von Hippel-Lindau disease, renal cell carcinoma is associated with what chromosome? what tumor suppresor gene?

Answer 5

3p25

VHL

Question 6

Wilm’s tumor is associated with what two chrom and what two tumor supressor genes respectively?

Answer 6

11p13 and 11p15, WT-1 and WT-2

Question 7

lung breast and colon cancer are all associated with what chrom and what tumor suppressor gene?

Answer 7

17p13.1, p53

Question 8

osteosarcoma and retinoblastoma are both associated with what chrom and what tumor suppressor gene?

Answer 8

13q14, Rb

Question 9

hereditary breast and ovary cancers are assoc with what chrom? what gene?

Answer 9

17q12-21

BRCA-1

Question 10

hereditary breast cancer is assoc with what chrom/tumor suppressor gene?

Answer 10

13q12-13, BRCA-2

Question 11

Adenomatous polyps and colon cancer is assoc with what chrom/tumor supressor gene?

Answer 11

5q21 and APC

Question 12

Colon cancer is assoc with what chrom/tumor supressor gene?

Answer 12

18q21 and DCC

Question 13

Neurofibromas is assoc with what chrom/tumor supressor gene?

Answer 13

17q11.2, NF1

Question 14

Acoustic neuromas, meningiomas are assoc with what chrom/tumor supressor gene?

Answer 14

22q12 and NF2

Question 15

presenting features of retinablastoma include

Answer 15

leukocoria (weird white reflection from the eye) and strabismus (eyes aren’t properly aligned), microscopy reveals small, round, blue cells; may have rosettes. Fmilial Rb is bilateral and assoc with osteosarcoma

Question 16

what is the rarest of the trisomies?

Answer 16

13- patau syndrome – death usually occurs within a yr

Question 17

what are the 3 viable trisomies?

Answer 17

21, 18 and 13