Healthy Living

CRISPR Helps Get Closer to Cure for Duchenne Muscular Dystrophy

CRISPR Helps Get Closer to Cure for Duchenne Muscular Dystrophy

CRISPR Helps Get Closer to Cure for Duchenne Muscular Dystrophy

Geneticists all over the world are going CRISPR crazy because they have found the Swiss knife for gene editing. Genes help create people's make-up, and genetic mutations are a well-known phenomenon for all the good and wrong reasons. Just any change in the gene would be called mutation, and they are responsible for the evolution of not only humans but all living beings, thus some of them even call mutations as raw material for evolution(1).

Some mutations do not go in the right direction and create diseases. Most of the muscular dystrophies are the result of mutations gone wrong. These faulty genetic mutations may happen due to various reasons, either due to the inheritance of weaker gene (or even collection of genes) or environmental factors.

To decode, read, compare and understand genes tools were developed in the late 20th century. Regarding genetic information of various ailments suddenly there was a burst in information. Many genetic mutations that led to muscular dystrophies were identified. Some were caused due o mutation of single gene and some combination of multiple genes. Usually Duchenne muscular dystrophy is caused by a single gene mutation and it is most common. It means that by any feasible gene therapy it can be treated.

Many problems could not be solved just by knowing what and where the gene mutations are. With this information only the problem could be identified and understood. In order to efficiently and successfully edit genetic materials, geneticists started their search for tools. This is where CRISPR comes into picture. It defends from various viral attacks and it is a part of bacteria’s adaptive immunity. For future reference a small copy of the viral genetic material is kept when a virus attacks the bacteria.  This genetic material can be edited if it repeatedly attacks the bacteria. This is how the threat is neutralized. Through a mechanism called CRISPR all this is possible. The genetic scissors over here is the enzyme Cas9, while the reference information is provided by g RNA

According to their use geneticists have been able to adapt the CRISPR by providing their copy of gene to the Cas9 to be edited. In case of Duchenne muscular dystrophy, a mutated copy of gene is provided to be edited.

The most risky thing over here is editing going wrong. Lots need to be discovered and understood in this technology although it is becoming an accurate technology. There are chances that new kinds of untreatable disease can be produced by this technology though the focus of the treatment is making genetic changes that are local and targeted and reducing the chances of inheritance. About human genetics still not everything has been understood.

Subject of gene expression or epigenetic is still yet to be understood. In order to treat genetic disorder it is not necessary to edit or delete the particular gene sequence. Changing the gene expression, rather than complete deletion making the specific gene inactive may also help. These methods are more physiological and much safer.

This concept on living forms first need to be tested and verified before it is tried on humans. On mice the effectiveness of gene editing has been shown by some studies.  In China, scientists were able to make mosquitoes resistant to malaria by editing their genes thus preventing the spread of disease. This technology can increase the production of livestock and treat many ailments. Still for human use this technology is yet to be proved to be safe.

In overcoming symptoms of muscular dystrophy, promising results have been shown by many experiments on mice. It is not necessary to edit the defective gene in all muscular cells, to make genetic therapy successful. It would be enough if small percentage of muscular cell is edited.

In Duchenne muscular dystrophy, there is deficit of dystrophin. Loss of muscle cells is progressive.  Thus even in the small number of muscle fibres, mutated gene is edited still they can take the place of defective muscle fibers and grow.

To make sure that only the targeted organs get the therapeutic agents, practical ways of targeted delivery needs to be found out. A complex of gold nano particles and CRISPR components has been created by the scientists. When locally in musculature they are injected, in muscles they carry out the editing process but its effect is minimal on the other tissues.