Cancer genetics Flashcards
What is an oncogene?
A gain of function mutation that can activate pathways to promote cellular growth.
What are the ways in which proto-oncogenes act as oncogenes?
- Hyperactive protein made in normal amounts.
- Normal protein made in hyper amounts.
- A new gene is made due to chromosome fusion.
What drug can be used against the Philadelphia chromosome (CML)?
Gleevec, an example of precision medicine!
What is an oncomir?
miRNA that behave as oncogenes by inhibiting tumor suppressor genes. Extremely potent
What is Ataxia Telandiectasia (A-T)?
A recessive chromosome instability syndrome that modulates cellular responses to DNA damage.
What are the symptoms of A-T and when do they appear/
First signs appear around age 2: lack of balance, slurred speech. Progressively degenerates to radiosensitivity, immunodeficiency, and predisposition to cancer.
What defect does radiation cause?
Double strand DNA break.
Do XP patients have radiosensitivity?
No.
What is a hallmark of A-T?
Chromosome restrictions on karyotype.
What is Fanconi Anemia?
A recessive chromosome instability syndrome of a FA protein complex that modulates cellular response to DNA damage.
What are symptoms of Fanconi Anemia?
Physical abnormalities (e.g. double thumb), bone marrow failure, malignancy
What is Bloom syndrome?
A recessive chromosome instability syndrome. The bloom complex and the FA complex work together and fail to respond to DNA damage.
What are the symptoms of Bloom syndrome?
Severe growth deficiency Otitis media Pneumonia Infertility Cancer
What do you see on a Bloom karyotype?
Excessive crossing over
What are 3 chromosome instability syndromes?
A-T
Franconi Anemia
Bloom Syndrome
