The genetic breakthrough of CRISPR-how it has the potential to change humanity forever By Mathujana Thirunavukkarasu, U5 A The four letters A, C, T and G represent the molecules that form our deoxyribonucleic acid, which modifies who we are from the moment of conception. Only 66 years ago, Watson and Crick discovered the complex structure of DNA, and for just over a decade, we have known all the letters in our DNA, and despite discovering small genetic adaptions to deleterious mutations, such as Alzheimer’s disease, only now have we found a method to directly edit DNA. Less than half a century ago, it was believed computers would take over everything, such as shopping and the stock market. Similarly, CRISPR-Cas 9 has the potential to change all of humanity forever. CRISPR is the acronym for “Clustered Regularly Interspaced Short Palindromic Repeats�. Put simply, scientists recognise the genome causing the health problem, to be able to create a specific guide-RNA, which is then attached to the DNA cutting enzyme, Cas 9, and finally introduced to the target cells. It locates the target letter sequence and cuts the DNA. Then, scientists edit the existing genome by modifying, deleting, or inserting new sequences, similar to the way we use spell check on Microsoft Word, for example. Whilst CRISPR has not only been able to shrink tumours in mice carrying human prostate cancer and liver cancer cells, it has also been able to cure HIV from a living organism, proving how successful this tool has already been. Additionally, the system has the ability for editing reproductive/germline cells which could be remarkably beneficial for discovering diseases at an early stage. This would mean any changes made in the cells, will be passed on from generation to generation. It is hugely controversial, more so than genome editing in somatic cells, (any cell of a living organism other than reproductive cells) which is ethically accepted due to the balance between benefits and risks. Whereas, editing germline cells brings up many ethical challenges.
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