USING THE CRISPR / CAS 9 GENE EDITING TOOL TO DEVELOP A CURE FOR DUCHENNE MUSCULAR DYSTROPHY

CRISPR, short for Clustered Regularly Interspaced Short Palindromic Repeats, is a revolutionary gene editing system that has the power to cut and paste any section of DNA and potentially cure many genetic diseases. CRISPR consists of two parts, with its partner enzyme “cas9” performing the cutting and pasting, and CRISPR being an RNA sequence that guides the enzyme to the proper location in the cell. It can be programmed to locate any gene, and can cut hundreds of bases or just a few. While CRISPR has also been applied to agriculture and other fields, the focus of this paper is on the use of this technology in the search for a cure for Duchenne muscular dystrophy (DMD), which affects one in every 3500 men. This paper will be organized into four main sections. The first two will cover background information on CRISPR and DMD, delving into topics such as the technicalities of how CRISPR works, as well as past attempts to cure DMD. The next section will investigate how CRISPR is being applied to muscular dystrophy by looking closely at one specific experiment which used a germline editing method to show muscle redevelopment in mice with DMD. Finally, the last section will cover the ethical and sustainability concerns related to CRISPR, and this will be followed with a conclusion that demonstrates why CRISPR is important to the conference and to engineering. Key Words—CRISPR/Cas9, Duchenne muscular dystrophy (DMD), ethics, gene, muscle development, mutation, RNA A REVOLUTION IN GENE EDITING The field of genetic engineering has seen many explosive discoveries over the past few decades, but few have carried with them the potential that is harbored by a technology known as Clustered Regularly Interspaced Short Palindromic Repeats, better known as CRISPR. This gene editing tool can remove any desired section of DNA, and then insert a replacement and repair the strand just like new. It has taken the field of genetics by storm due to its virtually limitless potential. CRISPR’S usage in agriculture and industry has already begun, but the focus of this paper will be on its development as a cure for genetic diseases, specifically Duchenne muscular dystrophy (DMD). For many of these diseases, DMD included, the mutation that causes the disease is well known, but unfortunately science has yet to discover a mechanism by which to fix it. CRISPR has the potential to be that mechanism, and the way in which it could do so will be the focal point of this paper. DUCHENNE MUSCULAR DYSTROPHY In order to fully comprehend the significance of applying CRISPR to find a cure for Duchenne muscular dystrophy, some background knowledge on the disease itself is necessary. The Muscular Dystrophy Association defines Duchenne muscular dystrophy as “a genetic disorder characterized by progressive muscle degeneration and weakness” [1]. Duchenne is one of nine types of muscular dystrophy, but it is the most common form among children. Duchenne muscular dystrophy occurs almost exclusively in boys, although there have been very rare cases in which it has been documented in girls. This is because DMD is due to a mutation in the gene that codes for the dystrophin protein, which is located on the X chromosome. Since women carry two X chromosomes, carriers of the disease have one proper form of the gene and one damaged copy, but only one is needed in order for production of dystrophin to be carried out effectively. In men, however, having only one X chromosome means that if they inherit the mutated form of the gene, they will express DMD [1]. Symptoms and Prognosis According to the Muscular Dystrophy Association, for children afflicted by DMD, muscle weakness typically begins between the ages of three and five, beginning in muscles located in the hip, thigh, and shoulder area, and later spreading to the extremities. This will continue to progress at a varying rate, but typically the child is forced into a wheelchair between the ages of seven and twelve. Outside of the physical ailment, it should be noted that DMD patients typically have no other issues, and are both cognitively and socially normal. However, as they progress into their teen years, it becomes increasingly difficult to maintain a normal life. During the teen years, the process of muscle degradation becomes more severe in the respiratory and cardiovascular systems, both of which tend to bring about more serious