MST 1 Revision- Lectures 1-9 Flashcards
What cannot be found through DTC genotyping?
a. Response to drugs
b. Whether you carry a certain allele
c. Accurate predictions for developing a disease
d. Ancestral information
c. Accurate predictions for developing a disease
What can reduce warfarin metabolism?
a. ARG to CYS mutation at AA 144
b. Duplicated rs1799853
c. Excess cytochrome P4 50
d. ARG to TRP mutation at AA 98
a. ARG to CYS mutation at AA 144
What is not part of the Snyderome?
a. Transcriptome
b. Proteome
c. Metabolome
d. T lymphocytes
d. T lymphocytes
• DTC genotyping companies may provide health reports indicating disease susceptibility.
F
What makes up the structure of haemoglobin?
a. Four alpha globin chains
b. Four alpha and four beta globin chains
c. Two alpha and two beta globin chains
d. Four myoglobin subunits
c. Two alpha and two beta globin chains
What is true about myoglobin?
a. It aids oxygen diffusion into the lungs
b. It decreases the solubility of oxygen
c. It has a low affinity for oxygen
d. It demonstrates Michaelis Menten kinetics
d. It demonstrates Michaelis Menten kinetics
• Leghemoglobins are the most primitive oxygen binding proteins and found primarily in bacteria.
F
plants
• Hemocyanin is a copper containing O2 transporter whilst Hemoerythrin is a O2 transporter lacking heme.
T
• The deoxygenated state of haemoglobin is also called the T state whilst the oxygenated form is called the R state.
T
What is true about the divergence of globin genes?
a. α and β globin are close together on chromosome 11, suggesting a recent divergence
b. β, γ and δ are less similar to each other than α
c. The most recent divergence occurred between β and δ and they only differ in 10/146 positions
d. α globin was the last globin to diverge
c. The most recent divergence occurred between β and δ and they only differ in 10/146 positions
What can somatic cell hybrids not be used for?
a. Gene mapping
b. Inducing totipotency via ES cells
c. Complementation
d. Dominance studies
b. Inducing totipotency via ES cells
What is aminopterin?
a. A cancer drug that blocks the de novo DNA synthesis pathway
b. An enzyme that is required to produce DNA via the salvage pathway
c. A substrate for Thymidine Kinase required for DNA synthesis
d. A compound that converts HGPRT+ to HGPRT-
a. A cancer drug that blocks the de novo DNA synthesis pathway
• Each globin protein contains one alpha subunit from the alpha gene.
F
• The majority of globin protein is α2β2.
T
• There are four alpha globin genes in the haploid genome.
F
• Mutations to βglobin can be detrimental to the foetus.
F
What is not a feature of Heriditary Methemoglobinemia?
a. Suffers are protected from malaria
b. It results in a ferric haem (Fe3+) which won’t reversibly bind O2
c. It can arise due to an AA change in a globin near haem
d. It can be due to a mutation in MetHb reductase
a. Suffers are protected from malaria
What is the role of MetHb reductase?
a. It converts Fe2+ to Fe3+ in order to oxygenate tissue
b. It is responsible for a Hb Lepore phenotype
c. It converts Fe3+ to Fe2+ which can bind oxygen
d. It leads to Heriditary Methemoglobinemia when overactive
c. It converts Fe3+ to Fe2+ which can bind oxygen
What are the molecular genetics of Sickle Cell Anaemia?
a. A mutation in the LCR leads to the over production of alpha globin
b. A single AA change causes a change from polar glutamic acid to non-polar valine in beta globin
c. A frame shift mutation results in an early stop codon and truncated globin proteins which aggregate
d. A single AA change causes a change from negatively charged glutamic acid to positively charged lysine
b. A single AA change causes a change from polar glutamic acid to non-polar valine in beta globin
What is not a consequence of sickle cell anaemia?
a. RBCs accumulate in the liver and the organ becomes enlarged
b. RBCs are destroyed and this results in anaemia
c. RBCs clump together and can result in local blood supply failure
d. Dilation of the heart can lead to heart failure
a. RBCs accumulate in the liver and the organ becomes enlarged
(spleen)
In general, what is thalassemia?
a. Chronic deficiency of alpha globin chains
b. An excess of beta globin and alpha globin chains
c. The disease that results when gamma globin production is not replaced by beta globin production in the foetus
d. Quantitative abnormalities of haemoglobin
d. Quantitative abnormalities of haemoglobin
What is linkage disequilibrium?
a. The term to describe the high rate of people diagnosed with both sickle cell anaemia and thalassemia
b. Alleles at separate loci associated with each other higher frequency than expected by chance
c. When alleles on the same chromosome are so far apart they do not form an association with each other
d. Linkage between two separate loci grows over time and many generations
b. Alleles at separate loci associated with each other higher frequency than expected by chance
What is false about thalassemia?
a. Alpha thalassemia can result in inclusion bodies with β4
b. Beta thalassemia leads to the precipitation of insoluble α4
c. β4 tetramers are absent in those with Alpha thalassemia
d. Beta thalassemia can often result in RBC degradation in the marrow and spleen
c. β4 tetramers are absent in those with Alpha thalassemia
• Hb Lepore and anti Lepore arise due to unequal crossover during meiosis.
T
• Countries where malaria is prevalent have a low level of sickle cell anaemia.
F
• HbS migrates more slowly than HbA during gel electrophoresis as it is missing a charge.
T
• People who are homozygous for Sickle Cell Anemia thrive because plasmodium has trouble parasitising their RBCs and they can survive easily as half their cells are non-sickle.
F
What is the phenotype of someone with two functional Alpha-genes?
a. Wildtype
b. HbH disease
c. Alpha thalassemia trait
d. Hb Barts Hydrops Fetalis
C
What makes up the Beta thalassemia phenotypes?
a. Asymptomatic heterozygotes are thalassemia intermedia
b. β+ and β(0) heterozygotes are thalassemia major
c. Those with one mild allele and concurrent alpha-thal or HPFH are thalassemia minor
d. Those with Thalassemia intermedia have symptoms, but don’t need transfusions
d. Those with Thalassemia intermedia have symptoms, but don’t need transfusions
What is false about B+ thal caused by a G to A mutation at position 110?
a. The protein product is normal as 18 bases are added to the coding sequence and 18 is divisible by 3
b. The alternative splicing pathway is favoured 90% of the time
c. The mutation within the intron results in a frame shift mutation in the coding sequence
d. The mutation results in a new splice acceptor site being created within the first intron
a. The protein product is normal as 18 bases are added to the coding sequence and 18 is divisible by 3
What is false about Haemoglobin E?
a. The causative mutation is found in the coding sequence of the Beta globin gene
b. A single base change leads to a Glu to Lys substitution and creation of HbE
c. The mutation results in a new donor site which impacts splicing and leads to a short exon 1
d. The mutation occurs within the first intron and leads to an extra splice site in the Beta globin gene
d. The mutation occurs within the first intron and leads to an extra splice site in the Beta globin gene
• Deletions are the primary cause of both alpha and beta thalassemia.
F
alpha
• It is possible to be born with zero functioning alpha genes.
F
• Northern blots are more specifc than dot-blot hybridisation.
T
• Globin chains are present in β+ and absent in β(0) individuals.
T
• β globin mRNA is absent in all β(0) individuals.
F
What demonstrates that there are additional regulatory sites for B-thal?
a. The Beta globin gene is turned off in mouse erythroleukemia cells
b. DNAase hypersensitive sites can be identified and correspond to regions of closed chromatin
c. Hybridisation of mouse erythroleukemia cells and human fibroblasts results in human beta globin production
d. Hybridisation of mouse erythroleukemia cells and human fibroblasts leads to the down regulation of all globin genes
c. Hybridisation of mouse erythroleukemia cells and human fibroblasts results in human beta globin production
What can happen if the beta globin gene promoter is deleted?
a. Alpha globin will accumulate and the foetus will die
b. Delta globin will be produced in adult tissue
c. Gamma globin synthesis does not cease due to a lack of competition
d. The delta and epsilon globin genes are not spliced out of mRNA transcripts
c. Gamma globin synthesis does not cease due to a lack of competition
Which gene expression modifier is matched to its correct description?
a. KLF1 directly activates HDAC
b. HDAC activates BCLIIA which activates HBG
c. KLF 2 and 4 activate HBB expression
d. KLF1 activates HBB expression through BCLIIA
d. KLF1 activates HBB expression through BCLIIA
What is false about globin regulation at the level of transcription?
a. MYB and KLF1 regulate each other
b. MicroRNAs can influence gamma and beta expression directly or through MYB
c. MYB is an oncogenic transcription factor
d. BCLIIA is often repressed by the action of microRNAs
d. BCLIIA is often repressed by the action of microRNAs
What is not a possible treatment for thalassemia?
a. Molecularly targeting and deleting the gamma globin promoter
b. Recurrent transfusions
c. Gene therapy
d. HDAC inhibitors and short chain fatty acids that inhibit histone demethylation
a. Molecularly targeting and deleting the gamma globin promoter
• The type of globin produced is due to competition between promoters.
T
• Full expression of a gene is still possible in the absence of the LAR.
F
What is not a trend that has been recently observed?
a. The age of first time mothers has increased
b. Incidence of aneuploidies increases with maternal age (e.g. 1 in 8 risk for 19 year old)
c. The age of mothers and human reproduction rate has increased over time
d. A 30 year old woman has a 1 in 21 chance of delivery a baby with aneuploidy
d. A 30 year old woman has a 1 in 21 chance of delivery a baby with aneuploidy
What is false about PGD?
a. Biopsy can be followed by FISH or PCR to detect the presence of mutations
b. It can only occur once implantation has occurred
c. IVF is used and a cell is sampled from the 8 cell stage
d. It can be used if there is a known family mutation or issues with recurrent chromosomes abnormalities
b. It can only occur once implantation has occurred
What is Intra Cytoplasmic Sperm Injection used for?
a. To create embryos that undergo PGD testing
b. To ensure a saviour child has a specific tissue genotype for their ill sibling
c. To reduce the risk of contamination with sperm DNA during PCR if PCR analysis is required
d. To aid with female infertility
c. To reduce the risk of contamination with sperm DNA during PCR if PCR analysis is required
What is false about Chorionic Villus Sampling and Amniocentesis?
a. Amniocentesis has an abortion risk of 3.2% whilst CVS has a 5% risk
b. Both are undertaken at 12 weeks gestation
c. Amniocentesis is recommended to mothers over 37 years
d. Care must be taken in CVS to separate maternal and foetal tissue
b. Both are undertaken at 12 weeks gestation
What is not a routine neonatal screening test?
a. Muscular Dystrophy
b. PKU
c. Hypothyroidism
d. Cystic Fibrosis
a. Muscular Dystrophy
What is not involved in screening for cystic fibrosis in newborns?
a. Those with high levels of IRT are recalled for further testing by a 12 mutation analysis
b. Those with only 1 mutation are not subjected to further testing
c. Those with 2 CF mutations are diagnosed with CF
d. The most common mutation is p.F508del
b. Those with only 1 mutation are not subjected to further testing
• Aneuploidy refers to the loss or gain of a set of chromosomes.
F
not set
• In 2013 the median age of first time mothers was 29.3 as opposed to 1986 when it was 25.4.
T
• When the risk is there, it is common to carry out foetal genetic testing for breast cancer, FAP and Familial Alzheimer’s disease.
F
• Ultrasounds are routine tests carried out once in a pregnancy at the 24 week stage.
F
12 and 20 weeks
• Trisomy 21 can be indicated by high levels of oestriol and low levels of hCG in maternal blood.
T
• NIPD can determine aneuploidies but not mutations in the foetus.
F
determines both
When wouldn’t an invasive test such as amniocentesis or chorionic villus sampling be used?
a. When there is a high risk of polyploidy
b. There is an abnormal maternal serum test in the second trimester
c. There is an abnormal ultrasound
d. There is a history of chromosome abnormality or single gene mutation
a. When there is a high risk of polyploidy
What was involved in the early attempted treatments of XSCID?
a. David Vetter died due to an intense immune response to receiving T cells transduced with functional ADA
b. Ashanthi DeSilva now receives periodic infusions of T cells transduced with a retroviral vector with a functional ADA gene
c. The most common treatment method utilises an adenoviral vector carrying the functional ADA gene
d. Ashanthi DeSilva died due to Epstein Barr virus contracted following a bone marrow transplant
b. Ashanthi DeSilva now receives periodic infusions of T cells transduced with a retroviral vector with a functional ADA gene
Which is not one of the most common viral gene therapy vectors?
a. Retroviral
b. Lentiviral
c. Parvoviral
d. Adeno-associated viral
c. Parvoviral
Which viral vector is described accurately?
a. Adeno-associated viral vectors have ssDNA that remains as an extra chromosomal entity
b. Retroviral vectors have dsDNA that can integrate or remain extra chromosomal
c. Adeno viral vectors have ssDNA that remains as an extra chromosomal entity
d. Lentiviral vectors have ssRNA that remains extra chromosomal in non-dividing cells
a. Adeno-associated viral vectors have ssDNA that remains as an extra chromosomal entity
What is not an advantage of non-viral gene therapy vectors?
a. Versatility
b. No size limit
c. Transfer efficiency
d. DNA protection
c. Transfer efficiency
What is false about XSCID?
a. It leads to a defective gamma-C chain which means STAT receptors can’t respond and lead to the maturation of lymphocytes
b. Suffers lack B, T and NK cells
c. A pseudotyped gammaretroviral vector was used to treat Rhys Evans
d. Gene therapy generally follows the in vivo route
d. Gene therapy generally follows the in vivo route
What is true about the gene therapy treatment for haemophilia?
a. A retroviral vector was used
b. The gene involved was Factor IX
c. The corrected gene was injected into the pancreas
d. ¾ patients risk developing leukaemia due to insertional mutagenesis
b. The gene involved was Factor IX
What happened to Jesse Gelsinger and Jolee Mohr?
a. Jesse was cured of Xscid and Jolee died from Epstein Barr virus following bone marrow transplantation
b. Jesse died due to an immune response against the adenoviral vector used to treat his OTC whilst Jolee died due to mixing gene therapy with a suppressed immune system
c. Both Jesse and Jolee developed leukemia as a result of retroviral vector insertional mutagenesis
d. Jesse was cured of OTC and Jolee dies from an adverse immune response to the same treatment
b. Jesse died due to an immune response against the adenoviral vector used to treat his OTC whilst Jolee died due to mixing gene therapy with a suppressed immune system
• Gene therapy was initially developed for hereditary, single gene defect diseases but it is now more commonly used to treat polygenic diseases.
T
• Most gene therapy clinical trials are focused on cardiovascular and immune disease.
F
cancer
• Ex vivo delivery involves directly introducing the vector to the patient whilst In vivo delivery first utilises cultured cells derived from the patient which are then reintroduced to the patient.
F
• There is no universal gene therapy vector to treat any disease.
T
• Lentivirus can only transduce cells which are dividing.
F
retrovirus only dividing cells
• A major advantage of viral gene therapy is the packaging capacity of the vectors.
F
• Physical non-viral methods of gene delivery increase the cell membrane permeability to plasmids
T
• Polyplexes are negatively charged complexes that bind DNA and interact with ligands on cell membranes to import the DNA into the cell.
F
+ charged
• Viral gene therapy has been used to treat sight disorder when the normal copy of defective RPE65 is injected between two layers of cells forming retina and therefore restoring photoreceptors.
T
• Naked DNA injections can be used to treat ischemic limb disease and ischemic heart disease.
T
What is not a requirement of gene therapy?
a. Know the specific gene defect
b. Have an available copy of the functional gene
c. Target cells should be able to be transfected
d. Transfer of the functional gene so it can be expressed transiently
d. Transfer of the functional gene so it can be expressed transiently
Which statement is false?
a. Adenoviral and Liposome vectors show high expression levels
b. Adeno-associated viral vectors can carry inserts up to 30kb large
c. Retroviral and lentiviral vectors can integrate into the genome
d. Inflammation is a risk when using adenoviral or adeno-associated vectors
b. Adeno-associated viral vectors can carry inserts up to 30kb large
Which type of haemoglobin is correctly matched to its relative abundance?
a. α2β2 90%
b. α2δ2 2.5%
c. α2β2 0.5%
d. α2γ2 50%
b. α2δ2 2.5%
What is not a required plasmid component to produce a Lentiviral vector?
a. Transfer vector (transgene with flanking LTRs)
b. Packaging vector
c. Reverse transcription/integration vector
d. Envelope vector
c. Reverse transcription/integration vector
What is false about Adeno-associated virus as a gene therapy vector?
a. It integrates specifically at AAVS1 on human chromosome 19
b. It has a small insert size, 4kb
c. It has a DNA genome with ITRs for replication, packing and specific integration
d. In utilises host cell Rep proteins which aids its expression of the transgene
d. In utilises host cell Rep proteins which aids its expression of the transgene
What is not an advantage of using Herpes virus as a viral vector?
a. It allows for stable gene expression
b. Non-dividing cells can be transduced
c. It can fit large DNA fragments
d. It has an affinity for neuronal tissue
a. It allows for stable gene expression
Which statement is correct?
a. CRISPR is the most expensive targeted nuclease system to use
b. ZFN is the most reliable and accurate targeted nuclease system
c. TALENS is a relatively cheap and accurate targeted nuclease system that is quick to use
d. CRISPR is a cheap targeted nuclease system with high reliability and accuracy
d. CRISPR is a cheap targeted nuclease system with high reliability and accuracy
What is not involved in CRISPR genome modification?
a. A cas9 protein that cleaves DNA
b. A 20 nucleotide gRNA sequence with an added NGG motif/PAM site
c. Wildtype Cas9 which requires two gRNAs to be active
d. A crispr RNA sequence (homologous to target site) and a trans-activating crisprRNA that recruits nuclease
c. Wildtype Cas9 which requires two gRNAs to be active
Which is a feature of Cas9 Nickase and not WT Cas9?
a. It ‘nicks’ a single strand
b. It only requires a single gRNA
c. It induces a double stranded break
d. Cleavage is highly efficient and good for random indels
a. It ‘nicks’ a single strand
• Monogenic diseases have showed the most success with gene therapy treatments.
T
• The lentiviral vector carrying the B-globin gene to treat B-thalassemia introduced the risk of sickling RBCs in recipients.
F
• Normal adult levels of haemoglobin are at about 14 g/dL.
T
• Following gene therapy, B-thal patients have higher levels of Hb (10g/dL) than normal adults which is likely a result of the artificial vector system over expressing beta globin.
F
• AAV integrates specifically at AAVS1 on chromosome 19 due to Rep proteins interacting with RBEs at Inverted terminal repeats (ITR).
T
