They Manage To Correct A Genetic Disease By Editing DNA

Noonan syndrome, fragile X syndrome, Huntington’s Korea, some cardiovascular problems…All of them are diseases of genetic origin that represent severe alterations in the lives of those who suffer from them. Unfortunately, until now it has not been possible to find a remedy for these evils.

But in cases where the responsible genes are perfectly located, it is possible that in the near future we can prevent and correct the possibility of some of these disorders being transmitted. This seems to reflect the latest experiments carried out, in which the correction of genetic disorders through gene editing

Gene editing as a method of correcting genetic disorders

Genetic editing is a technique or methodology through which it is possible to modify the genome of an organism, cutting out specific fragments of DNA and placing modified versions instead. Genetic modification is not something new. In fact, we have been consuming genetically modified foods for some time or studying various disorders and medications with genetically modified animals.

However, although it began in the 1970s, genetic editing has been imprecise and ineffective until a few years ago. In the nineties it was possible to direct action towards a specific gene, but the methodology was expensive and took a large amount of time.

About five years ago, a methodology was found with a higher level of precision than most of the methods used until now. Based on the defense mechanism with which various bacteria fight invasions by viruses, the CRISPR-Cas system was born in which a specific enzyme called Cas9 cuts the DNA, while an RNA is used that causes the DNA to regenerate in the desired way.

Both associated components are introduced, so that the RNA guides the enzyme to the mutated area so that it can be cut. Subsequently, a DNA template molecule is introduced that the cell in question will copy when reconstructed, incorporating the intended variation into the genome. This technique allows a large number of applications, including at a medical level, but it can cause mosaicism to appear and cause other unintended genetic alterations. That is why a greater amount of research is required in order not to cause harmful or unwanted effects.

A reason for hope: correcting hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a serious disease with a strong genetic influence and in which certain mutations are identified in the MYBPC3 gene that facilitate it. In it, the walls of the heart muscle are excessively thick, so that hypertrophy of the muscle (generally of the left ventricle) makes it difficult to emit and receive blood.

Symptoms can vary greatly or even not present obviously, but the occurrence of arrhythmias, fatigue or even death is common without any prior symptoms. In fact, it is one of the most frequent causes of sudden death in young people up to thirty-five years of age, especially in the case of athletes.

It is a hereditary condition and, although it does not have to reduce life expectancy in most cases, it must be controlled throughout life. However, the results of a study have recently been published in the journal Nature in which, through the use of genetic editing, the associated mutation has been eliminated in 72% of cases (42 of the 58 embryos used). to the appearance of this disease.

The technology called CRISPR/Cas9 has been used for this purpose, cutting out the mutated areas of the gene and rebuilding them from a version without said mutation. This experiment represents a milestone of tremendous importance, given that the mutation associated with the disease is eliminated and not only in the embryo being worked on, but it also prevents it from being transmitted to subsequent generations.

Although similar trials had been carried out previously, It is the first time that the intended objective has been achieved without causing other unwanted mutations Of course, this experiment was carried out at the same moment of fertilization, introducing Cas9 almost at the same time as the sperm in the egg, which would only be applicable in cases of in vitro fertilization.

There is still a way to go

Although it is still early and multiple replications and investigations must be carried out based on these experiments, thanks to this it could be possible in the future to correct a large number of disorders and prevent their genetic transmission.

Of course, more research is necessary in this regard. We must take into account that mosaicism can be caused (in which parts of the mutated gene and parts of the gene that are intended to be obtained are hybridized in the repair) or generation of other unintended alterations. It is not a completely verified method, but it gives rise to hope.