CRISPR and Sickle-Cell Disease

What is the purpose of the CRISPR-based therapy exa-cel?

• To cure sickle-cell disease

• To alleviate pain caused by sickle-cell disease

• To increase the production of fetal haemoglobin

• To prevent vaso-occlusive crises

What is the main concern regarding off-target edits in CRISPR–Cas9 therapies?

• Introduction of unwanted mutations

• Increased risk of cancer

• Inadequate genetic diversity in the analysis

• Insufficient sampling of cells from sickle-cell disease patients

What is the potential long-term complication associated with gene-altering therapies for sickle-cell disease?

• Increased risk of vaso-occlusive crises

• Development of blood cancers

• Ineffective production of fetal haemoglobin

• Loss of natural DNA-repair mechanisms

How many participants were involved in the clinical trial of exa-cel?

• 9

• 19

• 29

• 39

What is the role of the Cas9 enzyme in the exa-cel therapy?

• To cut both strands of DNA

• To guide the enzyme to the target stretch of DNA

• To stitch the DNA strands back together

• To disable the BCL11A gene

What is the main function of fetal haemoglobin in the treatment of sickle-cell disease?

• To alleviate pain

• To prevent clumping of blood cells

• To enable oxygen transport

• To repair DNA sequences

What is the potential risk associated with modifying blood stem cells in gene-altering therapies?

• Increased risk of vaso-occlusive crises

• Development of blood cancers

• Ineffective production of fetal haemoglobin

• Loss of natural DNA-repair mechanisms

What is the purpose of disabling the BCL11A gene in exa-cel therapy?

• To cure sickle-cell disease

• To alleviate pain caused by sickle-cell disease

• To increase the production of fetal haemoglobin

• To prevent vaso-occlusive crises

What is the potential risk associated with off-target edits in CRISPR–Cas9 therapies?

• Introduction of unwanted mutations

• Increased risk of cancer

• Inadequate genetic diversity in the analysis

• Insufficient sampling of cells from sickle-cell disease patients

What is the main function of the CRISPR–Cas9 genome editing system in exa-cel therapy?

• To cut both strands of DNA

• To guide the enzyme to the target stretch of DNA

• To stitch the DNA strands back together

• To disable the BCL11A gene