Genetics

Question 1

PTEN mutation + intestinal hamartoma =

Answer 1

PTEN mutation + intestinal hamartoma = cowden disease

Question 2

Sis

Answer 2

Sis = Growth factor

Growth factors e.g. Sis grow up

Question 3

Myc

Answer 3

Myc = Transcription factor

Myc tuns sounds to -e

Question 4

RET

Answer 4

REceptor tyrosine kinase e.g. RET

Question 5

Src

Answer 5

Cytoplasmic tyrosine kinase e.g. Src - Sytoplasmic

Question 6

Ras

Answer 6

Regulatory GTPases e.g. Ras – Rans to regulate

Question 7

NFT1

Answer 7

1s= Diagnosed first - present earlier due to learning difficulties

Learning difficulties, no hearing loss, bigger limbs (plexiform neurofibroma).

AD, Ch 17

Question 8

NFT2

Answer 8

No learning difficulties unlike 1,
Present later - detected 18-24
acoustic neuroma,
AD, Ch 22, merlin

Question 9

Peutz-Jeghers syndrome

Answer 9

Jegher puked brown bits all over him…
= Pigmented lesions on lips, oral mucosa, face, palms and soles

He swallowed some (GI) = Hamartomatous polyps in GI tract (mainly small bowel)

He was a big guy (AD inheritance)

He intusscepted him - Intestinal obstruction e.g. intussusception (which may lead to diagnosis)

Made him bleed = GI bleeding

The responsible gene encodes serine threonine kinase LKB1 or STK11

AD, CH 19

Question 10

FAP

Answer 10

Duodenal polyps - commonest extra colonic lesion in FAP.

o Gastric fundal polyps seen in 50% of patients.
o Skull osteomas are seen in Gardeners syndrome variant of.
o Thyroid CA, epidermoid cysts, multiple colonic polyps
o High grade dysplasia - panproctocolectomy
AD, Ch 5

Question 11

MEN 1

Answer 11

MEN 1: AD Ch 11

Question 12

MEN II

Answer 12

All tend to have medullary carcinoma of the thyroid as a presenting feature.

A/W phaeochromocytomas
AD - RET Proto-oncogene (Ch 10)

2B - half are sporadic

Question 13

Li-Fraumeni

Answer 13

P53 tumour suppressor loss, autosom dominant

80% sarcoma, breast, brain and adrenal, high risk of leukaemia

AD, CH 17

Question 14

Lynch Syndrome

Answer 14

80% Colorectal AND/OR OVARIAN (Lynch you and your sister)

o Amsterdam criteria
o FAP excluded

Hereditary nonpolyposis colorectal cancer
AD, Ch 2/3/7
o Mutations of mismatch repair genes

Amsterdam criteria
Three or more family members with a confirmed diagnosis of colorectal cancer, one of whom is a first degree (parent, child, sibling) relative of the other two.
Two successive affected generations.
One or more colon cancers diagnosed under age 50 years.
Familial adenomatous polyposis (FAP) has been excluded.

Question 15

Gardners syndrome

Answer 15

Familial Colorectal polyposis

AD, APC gene Ch 5

Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts
Desmoid tumours are seen in 15%

Colectomy to reduce CA risk

Question 16

Von Hippel-Lindau Syndrome

Answer 16

retinal and cerebellar hemangiomas

AD, VHL tumour suppressor Ch3

Question 17

Marfan’s – defect in

Answer 17

Marfan’s – defect in fibrillin, FBN1 mutation AD, Ch15