Genetic Modification and Gene Therapy Questions - Answers and Explanations

Question: 1 Which of the following are TRUE about transcription? (Select all that apply) Polymerizes A, G, C, and T ribonucleotides to form the pre-mRNA before splicing Makes an RNA strand that is complementary to a DNA strand Requires an RNA primase to bind to the promoter for initiation Produces a polyadenine tail on the 3’ end of the pre-mRNA Can start in the absence of transcription factors if the DNA structure is open as euchromatin 1 points

Question: 2 Adeno-associated viruses (AAV): Integrate their DNA into a random place in the genome Insert their DNA into a specific place on chromosome 19 Cannot integrate their DNA into the host cell genome Can only integrate their DNA into the X chromosome 1 points

Question 3 Which of the following is a common limitation for both gene guns and retroviruses when they are being used to modify cells? Random integration of the DNA into the host cell genome Small size of the DNA construct that can be inserted Can only be used on cells with the appropriate extracellular receptors Requires a trained operator to use specialized equipment 1 points

Question 4 Which of the following could be used as a selective marker for identifying or isolating genetically-modified cells? (Select all that apply) Gene that produces a noncoding siRNA Gene that is translated to produce mitochondrial proteins Gene that confers antibiotic resistance Gene that encodes green fluorescent protein Gene that is translated to produce tRNA molecules 1 points

Question 5 The LMO2 gene is: A proto-oncogene that was activated by insertion of the transgene in SCID-X1 gene therapy clinical trials The OMIM name for the gene that causes ADA-SCID in both XY males and XX females A gene whose activation downregulates adenosine deaminase activity to cause ADA-SCID The X-linked gene that displays sex-linked recessive inheritance to cause SCID-X1 in XY males 1 points

Question 6 Why is myeloablative conditioning sometimes needed when CD34+ hematopoietic progenitor cells are chosen for genetic modification in SCID patients? To prevent the growth of leukemic cells that arise as a result of the gene therapy treatment To damage autologous bone marrow so that it will no longer produce the incorrect proteins To destroy the adipose tissue that has replaced the nonfunctional hematopoietic cells To make space for sufficient engraftment of gene-modified cells 1 points

Question 7 Patients with retinitis pigmentosa suffer from retinal degeneration as a result of: Solid deposits in the vitreous humor Neural overstimulation Corneal breakdown Photoreceptor death 1 points

Question 8 The mutation that causes Leber’s hereditary optic neuropathy is in the: IL2Rg gene RPE gene mtND4 gene RPGR gene 1 points

Question 9 Why is it important to look at vector shedding in gene therapy trials? To limit the replicative ability of the vector to only the patient To prevent modification of non-target cells in the patient To ensure that the vector will not get into another patient To find ways to stop the vector from leaving the patient’s body 1 points

Question 10 Etranacogene dezaparvovec is being explored for its ability to treat: (Select all that apply) Hemophilia B Fanconi anemia Hemophilia A Christmas disease Von Willebrand disease 1 points

Question 11 A nitrogenous base that can be found in DNA but not in RNA is . 1 points

Question 12 During the splicing process, are spliced together while are removed from the pre-mRNA. 1 points

Question 13 When a mutation occurs that inserts a premature stop codon into an mRNA chain, the incorrect mRNA will be broken down by the process of -mediated decay. 1 points

Question14 Using a/an method of delivering a transgene, either using a viral or nonviral vehicle, would be the best choice for modifying hematopoietic stem cells because those cells can be easily isolated by removing bone marrow from the patient. 1 points

Question 15 Temporary modification of a cell, in which the transgene’s expression is limited in length rather than being stably expressed, is known as transfection. 1 points

Question16 A/an forms when a dendrimer mediates entry of a DNA construct into a cell; the construct must escape to be released into the cell. 1 points

Question 17 A person who has one dominant and one recessive allele for ADA-SCID is said to be in their genotype. 1 points

Question 18 A mutation in the gene on the X chromosome is the cause of X-linked SCID in XY males. 1 points

Question 19 About 1/3 of hemophilia patients are unable to use recombinant clotting factors because they have developed against the clotting factor that minimize their effectiveness. 1 points

Question 20 Patients who were treated with valoctocogene had that were dramatically decreased over time and, as a result, used very little recombinant factor VIII after receiving the gene therapy vector. 1 points