Chap 22

Question 1

Genetic counselor

Answer 1

Health care professional helps patients and their families navigate the path of genetic testing.

Question 2

Genetic counseling

Answer 2

• Pediatrics, and prenatal care.
• Branched into specialties such as cancer, cardiovascular disease, neurology, hematology and ophthalmology.

Question 3

Genetic Screening and Testing

Answer 3

Identifying mutations can help in diagnosis and choosing treatments

Question 4

Preimplantation genetic diagnosis

Answer 4

• Focus on disease
• Earliest test done on embryo following in vitro fertilization

Question 5

Prenatal Testing

Answer 5

• Chorionic villus sampling
• Amniocentesis
• Maternal serum markers - Noninvasive prenatal testing of cell-free fetal DNA done later in pregnancy

Question 6

Genetic Testing of Newborns

Answer 6

• Screening identifies infants at high risk of having certain
  genetic diseases that are “actionable”
• DNA testing
• Mass spectrometry detects atypical metabolites

Question 7

Genetic Testing of Adults

Answer 7

• To detect increased risk of developing certain cancers
• Tests can identify carriers of more than 1,000 recessive disorders.

Question 8

Treating Genetic Disease

Answer 8

• Removing an affected body part
• Replacing an affected body part or biochemical with material from a donor
• Delivering pure, human proteins derived from recombinant DNA technology
• Refolding correctly a misfolded protein
• Blocking gene expression (gene silencing)
• Using gene therapy to add wild type alleles without removing mutant alleles
• Using gene editing and genome editing to replace, delete, or add alleles

Question 9

Protein-Based Therapies

Answer 9

Adding digestive enzymes to applesauce for a child with disease. (CF, hemophilia)

Question 10

3 Type of Protein-Based Therapies

Answer 10

• Enzyme replacement therapy
• Substrate reduction therapy
• Pharmacological chaperone therapy

Question 11

Enzyme replacement
and substitution
therapy

Answer 11

Recombinant human enzyme infused to compensate for deficient
or absent enzyme

Question 12

Substrate reduction
therapy

Answer 12

Oral drug reduces level of substrate so enzyme can function more effectively

Question 13

Pharmacological
chaperone therapy

Answer 13

Oral drug binds misfolded protein, restoring function

Question 14

Gene Therapy

Answer 14

Delivers working copies of genes to specific cell types or body parts, typically aboard modified viruses

Question 15

Germline gene therapy

Answer 15

Gamete or zygote alteration; heritable; not done in humans; creates transgenic organisms

Question 16

Somatic gene therapy

Answer 16

Corrects only the cells that a disease affects; not heritable

Question 17

Ex vivo gene therapy

Answer 17

applied to cells outside of body that are then returned

Question 18

In vivo gene therapy

Answer 18

applied directly to an interior body
part.
most invasive

Question 19

Delivery of Gene Therapy

Answer 19

• Using viral vector that already remove the defective gene and adding corrective gene

Question 20

Sites of Gene Therapy

Answer 20

• Endothelium: can secrete into bloodstream
• Muscle: good blood supply
• Liver: can regenerate
• Lungs: aerosol spray

Question 21

Adenosine deaminase (ADA) deficiency.

Answer 21

• The first gene therapy
• A form of severe combined immune deficiency disease
• Absence of ADA enzyme causes build up of deoxyATP
• Destroys T cells, thereby causing susceptibility to
  infections and cancer.

Question 22

Strimvelis

Answer 22

Gene therapy that uses a patient’s own haematopoietic stem cells, the precursor cells for blood and immune cells,
to correct ADA mutation.

Question 23

Sickle Cell Disease

Answer 23

Single-base mutation in beta subunit causes sickle cell disease

Question 24

Sickle Cell Disease treatment

Answer 24

• Using hematopoietic steam cell
• Using viral vector carrying modified beta-globin gene

Question 25

Gene therapy vs Gene Editing (CRISPR-Cas9)

Answer 25

• Gene therapy adds correct DNA sequences
• Gene editing corrects DNA sequences by adding, deleting, or replacing DNA at the site of mutation