Ch. 22 Flashcards
(16 cards)
Genetic Counseling
Personal info; genetic screening for population and genetic test for individual
How do protein-based therapies help?
If any enzyme is deficient or its activity blocked, substrate builds up and the product is deficient
What are the three general approaches for counteracting lysosomal storage diseases?
enzyme replacement therapy, substrate reduction therapy, pharmacological chaperone therapy
Enzyme replacement and substitution therapy
recombinant human enzyme infused to compensate for deficient or absent enzyme
substrate reduction therapy
oral drug reduces level of substrate so enzyme can function more effectively
pharmacological chaperone therapy
oral drug binds misfolded protein, restoring function
ex vivo gene therapy
applied to cells outside of body that are then returned (IV infusion or spinal fluid)
remove cells- add therapeutic gene- return cells
in vivo gene therapy
applied directly to interior body part (catheter inserted and snaked to appropriate organ) - most invasive
How were viral vectors created?
removing genes that cause symptoms/alert immune system to infection and add corrective gene
What do viral vectors do?
deliver DNA cover technology
Germline gene therapy
gamete or zygote alteration; heritable - not done in humans and creates transgenic organisms
CRISPR-Cas9 on embryo edit to prevent HIV (knock out CCR5 gene in embryo)
Somatic gene therapy
corrects cells that disease affects; not heritable
What is ADA deficiency?
adenosine deaminase (ADA) deficiency; a form of severe combined immune deficiency
How did gene therapy help ADA deficiency?
absence of enzyme causes build-up of deoxyATP (destroys T cells, which thereby causes susceptibility to infections and cancer)
What is strimvelis?
form of gene therapy that uses patient’s own haematopoietic stem cells, precursor cells for lbood and immune cells, to correct ADA mutation
How does gene therapy treatment help sickle cell disease?
Bc hemoglobin is 4 pt molecule and single based mutation in beta subunit causes sickle cell: increases expression of fetal hemoglobin gene OR modify the DNA of beta globin gene to more like fetal hemoglobin (less likely to aggregate)
