Genetics Flashcards
Which gene mutation is a/w Breast Ca & Pancreatic Ca ??
BRCA2
Which cancer is a/w TP-53 mutation ??
Li- Fraumeni synd.
- A D inheritance
- It normally functions as a tumour suppressor gene
- a/w increased risk of Bone & Soft tissue cancer ; even breast cancer
Which cancers are a/w BRCA2 mutation ??
Breast & Ovary
Pancreatic
Prostate
Stomach
Bile duct & GB
Melanoma
Gene mutation a/w Burkitt’s Lymphoma ??
c-myc gene
t [8, 14]
What is Peutz- Jeghers synd. ??
- A D
- Perioral & mucosal melanocytic pigmentation
- Hamartomatous polyp
a/w Colorectal Ca, Gastric, Small bowel & Pancreatic Ca - increased risk of Breast Ca»Ovarian»Cervical
What is Gardner synd. ??
Famial Adenomatous Polyposis
- a/w Early onset Colon Ca
- Can also cause Osteomas, Epidermoid cyst
What is Lynch synd. ??
HNPCC
- a/w Early presentation, mean age of dx. 44- 61 yrs
- a/w GASTRIC & ENDOMETRIAL Ca
Fabry’s disease inheritance pattern ??
X- linked Recessive disorder
BRAF mutation ??
encodes B-raf protein
- MAP-kinase signalling pathway => regulates Cell division & differentiation
- Malignant melanoma
How to differentiate b/w Marfan’s & Homocystinuria ??
- Fibrillin 1 deficiency + NOT a/w low IQ + Upward lens dislocation
- Cystathione Beta-synthase deficiency + Low IQ + Downward lens dislocation + A R + VTE & MI
What is Pseudoxanthoma elasticum ??
ATP-binding Cassette protein, family C no. 6 mutation
- Puckered chicken skin
- Angiod retinal streaks
- Accelerated CVS disease
Below what age does the the Abd. USS screening of ADPKD is (-)ve
< 20 yrs
Gene involved in A R Polycystic Kidney Disease ??
PKHD1
What is DNA Methylation ??
Suppresses gene transcription
- occurs at 5th position of Cytosine, has the specific effect of reducing gene expression
How are mitochondrial disorders inheritted ??
Maternal lineage
What is the best way to edit the genome ??
CRISPR/Cas9 technology
What percentage of human genome is made of Non-coding sequence ??
90% of genome is comprised of Non-coding DNA
What are the cell cycle phases ??
G 0: Resting phase (eb.- hepatocytes, Neurons)
G 1:
- Increase in size
- Determines the LENGTH of Cell Cycle
- Under p53 influence
S phase: DNA, RNA & Histone synthesis; Centromere duplication
G 2 : Cell continue to increase its size
M : Mitosis- Cell division
Name the following about the Cell Cycle
- Under p 53 influence ??
- Determines the length of Cell C ??
- Centromere Duplication ??
- Shortest phase of Cell C ??
- G 1
- G 1
- S phase
- M phase
Name the Regulatory proteins of the following
- G 1 phase ??
- Transition from G 1 to S phase ??
- S phase ??
- G 2 phase ??
- Cyclin D/ CDK4, Cyclin D/ CDK6
- Cyclin E/ CDK2
- Cyclin A/ CDK2
- Cyclin A/ CDK1
What are the phases of Mitosis ??
Prophase: Chromatin condenses in the nucleus
Prometaphase: Nuclear memb. breaks down + Microtubules attach to Chromosomes
Metaphase: Chr. aligned at MIDDLE of cell
Anaphase: Paired Chr. SEPERATE at Kinetochores & move to the opposite end
Telophase: Chromatids arrive at the poles of the cells
Cytokinesis: Actin-Myosin complex in the centre of the cell contracts => Cell being pinched into 2 daughter cells
What are Microtubules ??
Components of Cytoskeleton of Cytoplasm
- Guide movt. during intracellular transport
- Helps to BIND internal organelles
Cylindrical str. composed of Alpha + Beta tubulin subunits => polymerize to form PROTOFILAMENTS
- They are POLARIZED
How does molecular transport occur with the help of Microtubules ??
Attachment proteins called DYNEIN & KINESIN move up & down the Micro-tubules facilitating the movt. of organelles around the cell
- Dynein=> moves in Retrograde fashion- DOWN the microtubules towards the centre of cell [+ve => -ve]
- Kinesin=> moves in Anterograde fashion- UP the microtubule away from the centre, [-ve ==> +ve]
Name the Cell Surface Proteins a/w the following cells
- Haematopoietic Stem Cells ??
- Helper T cells ??
- Cytotoxic T cells ??
- Regulatory T cells ??
- B cells ??
- Macrophages ??
- NK cells ??
- CD 34
- CD4, TCR, CD3, CD28
- CD8, TCR, CD3, CD28
- CD4, CD25, TCR, CD3, CD28
- CD19, CD20, CD40, MHC-II, B7
- CD14, CD40, MHC-II, B7
- CD16, CD56