Gene Function to Clinic Flashcards
What proportion of breast cancers are associated with BRCA mutations?
5-10% all breast cancers.
-16% of breast cancer in
What proportion of breast cancers are associated with BRCA mutations?
5-10% all breast cancers.
-16% of breast cancer in
What chromosome is associated with early onset familiar breast cancer?
Chromosome 17q21.
What is the risk of developing breast cancer for women in the USA?
12%.
-85% with BRCA 1/2 mutation
What is the risk of developing ovarian cancer for women in the USA?
How does prophylactic surgery reduce breast and ovarian cancer risks?
Mastectomy - reduces risk by 90%.
Ovaries - reduces risk by 85%.
What is non-penetrance?
Genotype fails to manifest itself in phenotype because of modifying factors.
What are the main features of Treacher-Collins syndrome?
Abnormal development of bones / tissues in face.
- lack of migration of neural crest cells to face
- small chin, constricted airways, etc
What are the main prenatal tests, and when are they carried out? (3)
- Amniocentesis (~17w)
- Chorionic villus biopsy (~11w)
- Non-invasive testing (~10w)
What is pre-implantation testing (on cell from embryo) mainly used for?
- Monogenic disorders.
e. g. CF, beta-thalassaemia - Chromosome abnormalities
What is non-disclosure testing?
Parents do not wish to know if they are carriers, but wants children who do not have the genetic mutation.
-e.g. Huntington’s
What mutation is linked to obesity?
Leptin.
-hormone secreted by adipose cells to tell the brain to stop eating
What hormone opposes leptin?
Ghrelin.
-secreted when stomach is empty
What is gene therapy?
Introduction of functional DNA to replace mutated genes.
What is Leber’s congenital amaurosis (LCA)?
Inherited blindness (autosomal recessive). -gene therapy by subretinal injection improves vision
What gene is associated with Leber’s congenital amaurosis (LCA)?
RPE65 mutation.
