genetic links

Question 1

li fraumeni syndrome

pathophys and diagnosis

Answer 1

Autosomal dominant
female has nearly 100% chance of developing breast cancer
Consists of germline mutations to p53 tumour suppressor gene
High incidence of malignancies particularly sarcomas and leukaemias
Diagnosed when:

*Individual develops sarcoma under 45 years
*First degree relative diagnosed with any cancer below age 45 years and another family member develops malignancy under 45 years or sarcoma at any age

Question 2

BRCA 1 and 2

links with what cancers, what chromosomes

Answer 2

Carried on chromosome 17 (BRCA 1) and Chromosome 13 (BRCA 2)
Linked to developing breast cancer (60%) risk.
Associated risk of developing ovarian cancer (55% with BRCA 1 and 25% with BRCA 2).
BRCA2 mutation is associated with prostate cancer in men

Question 3

Lynch Syndrome

Answer 3

Autosomal dominant
Develop colonic cancer and endometrial cancer at young age
80% of affected individuals will get colonic and/ or endometrial cancer
High risk individuals may be identified using the Amsterdam criteria

Question 4

Amsterdam criteria

Answer 4

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 5

Gardners syndrome

Answer 5

• Autosomal dominant familial colorectal polyposis
• Multiple colonic polyps
• Extra colonic diseases include: skull osteoma, thyroid cancer and epidermoid cysts
• Desmoid tumours are seen in 15%
• Mutation of APC gene located on chromosome 5
• Due to colonic polyps most patients will undergo colectomy to reduce risk of colorectal cancer
• Now considered a variant of familial adenomatous polyposis coli

Question 6

9 cancers linked to li fraumeni

Answer 6

soft tissue sarcoma - muscles, tendons, fat, lymph and blood vessels
osteosarcoma
breast cancer
glioma (brain)
choroid plexus carcinoma
medullablastoma
neuroblastoma
adrenocortical carcinoma
acute myeloid leukemia

Question 7

Features of gardner’s syndrome

Answer 7

non cancerous tumours in bone and soft tissue
extra teeth
Osteomas.
Desmoid tumors.
Lipomas.
Fibromas.
Adenomas.
Epithelial cysts (cysts under your skin).
CHRPE (congenital hypertrophy of retinal pigment epithelium), which affects your retinas.
Stomach cancer.
liver cancer
colon cancer