Genetic Disorders
- A genetic disorder is a disease that is caused by a change, or mutation, in an individual’s DNA sequence.
- These mutations can be due to an error in DNA replication or due to environmental factors, such as cigarette smoke & exposure to radiation, which cause changes in the DNA sequence.
Gene Therapy
- Technique to replace defective genes with healthy genes to treat genetic disorders.
- Artificial method that introduces DNA into the cells of the human body.
- First developed in 1972, but has limited success.
- Two types of gene therapy: Somatic gene therapy and germline gene therapy.
Gene Editing
- Gene editing is a technique of making specific changes to the DNA at a specific sequence.
- For this DNA is inserted, deleted, modified or replaced in the genome.
- For this CRISPR CAS9 Scissor is used.
- It involves making cuts at specific DNA sequences with enzymes called ‘engineered nucleases’.
CRISPR-Cas9
- CRISPR stands for ‘Clustered Regularly Interspaced Short Palindromic Repeats’
- It is the most common, cheap & efficient system used for genome editing.
- CRISPR is the DNA-targeting part of the system which consists of an RNA molecule, or ‘guide’, designed to bind to specific DNA bases through complementary base-pairing.
- Cas9 stands for CRISPR-associated protein 9, & is the nuclease part that cuts the DNA.
- The CRISPR-Cas9 system was originally discovered in Bacteria that use this system to destroy invading.
