GENETICS

Question 1

what genetic mutation is seen in Down Syndrome

Answer 1

meiotis non-disjunction ch21
(meiosis I, anaphase)

unbalanced robertsonian translocation - only occurs in 4%

Question 2

preponderance

Answer 2

greater number or dominance

i.e. preponderance of lymphocytes

Question 3

nonsense mutation

Answer 3

premature stop codon

UGA
UAG**

**UAA

i.e.
duchenne muscular dystrophy (+ frameshift mutation)
B thalassemia
CF
hurler
marfan (less common)

Question 4

Li Frumani (AD) has mutation in ____ on chromosome ____

Answer 4

TP53
Ch 17

associated cancers:
Soft tissue sarcomas
Breast cancer
Leukemia
Adrenal cortical carcinoma
brain tumors and osteosarcoma

Question 5

genetic test used to identify point mutation (mutatino within single gene)

Answer 5

gene sequencing

cannot detect whole gene deletion

Question 6

what are neoantigens

Answer 6

new antigens produced by tumours - arise from mutations in cancer cells

better responses to **immune checkpoint inhibitors **

Not present in normal (non-mutated) tissues
Recognized as foreign by the immune system
Derived from mutated proteins, gene fusions, or aberrant splicing