Explain what the term genetic engineering means.
Outline how an inherited eye disease, such as LCA2, is treated using gene therapy.
Suggest why the eye is a suitable organ for gene therapy.
Describe the results of the clinical trial data shown in Fig. 3.2.
Another treatment being investigated for LCA10 is to use a gene editing tool called the CRISPR/Cas9 system. The CRISPR/Cas9 system uses a short length of RNA called guide RNA. Guide RNA is complementary to the target DNA and is attached to a nuclease enzyme called Cas9. Cas9 breaks phosphodiester bonds in DNA. The cell repair mechanisms repair the cut in DNA after the modification has taken place. • A vector carries Cas9 and two specific guide RNAs to the photoreceptor cells. • They act on the section of DNA which contains the mutation. • Exon X is no longer added to the mRNA. Explain how this method used to treat LCA10 is an example of gene editing.