CRISPR

CRISPR is a technology used for editing DNA, enabling precise changes to the genetic information within a cell. DNA contains the instructions that govern how cells function and produce proteins, and CRISPR makes it possible to target a specific location within that sequence and modify it. For example, it can be used to repair a defective genetic segment, disable a harmful gene, or introduce a desired change into the DNA.

CRISPR is based on a natural defense mechanism that bacteria use against viruses. In this system, a bacterium preserves a small segment of the genetic material from a virus that has attacked it, creating a kind of “memory” of the invader. If the same virus attacks again, the bacterium uses the stored genetic segment to recognize the virus’s DNA and guide a cutting enzyme to the targeted sequence. The enzyme then cuts the viral DNA, neutralizing the threat and preventing the infection from spreading.

Researchers adapted this natural mechanism and transformed it into a tool for DNA editing. Instead of directing the system to identify and cut viral DNA, it can be programmed to recognize a specific location within the DNA of a living cell and make targeted modifications at that site.

The system generally relies on two main components: a short RNA molecule, which serves as a guide and directs the system to the precise location in the DNA, and a cutting enzyme called Cas9, which cuts the DNA at that point. After the cut is made, the cell activates its natural repair mechanisms, and at this stage the desired change can be introduced into the genetic sequence.

What sets CRISPR apart from earlier genetic editing methods is that it is relatively simple to use, more efficient, and significantly less expensive. The technology has a wide range of applications in human medicine, including research and the development of treatments for genetic blood disorders, certain types of cancer, and eye diseases. At the same time, it is also widely used in agriculture, for example in the development of crop varieties that are more resistant to drought, disease, and pests.

At the Dangoor Center for Personalized Medicine, researchers are also studying the use of CRISPR technology for the development of genetic therapies. One of the studies focuses on “bubble boy disease,” a severe genetic disorder in which the immune system does not develop properly. The research explores the possibility of using CRISPR to correct the genetic defect in blood cells, enabling them to develop into healthy immune cells.

This research demonstrates the potential of CRISPR in personalized medicine; however, it remains an area of ongoing research and is not yet available as a routine treatment for every patient. More broadly, alongside its enormous potential, CRISPR also raises important ethical questions, particularly regarding the limits of intervention in the genomes of living organisms and the possible implications for future generations.

Frequently Asked Questions

1. What is CRISPR?

CRISPR is a technology that allows scientists to edit parts of the genome by removing, adding, or altering DNA sequences. It is considered one of the most precise, rapid, and cost-effective tools currently available for modifying genetic material. The technology is based on a natural bacterial immune system that bacteria use to cut the DNA of invading viruses.

2. How does CRISPR technology work?

CRISPR technology operates through a combination of a cutting enzyme called Cas9 and an RNA molecule programmed to recognize a specific genetic sequence. When introduced into a cell, the RNA molecule “scans” the genome until it locates a sequence that matches the target sequence. At that point, the Cas9 enzyme cuts the DNA strand.

After the cut is made, the cell activates its natural repair mechanisms. One mechanism, known as NHEJ (non-homologous end joining), often results in the disabling of genes. Another mechanism, called HDR (homology-directed repair), makes it possible to insert a new or corrected DNA sequence with a high degree of precision.

3. Which diseases can be treated using CRISPR technology?

CRISPR technology is already being used in clinical trials to treat diseases caused by mutations in a single gene, including sickle cell anemia and beta thalassemia. By 2026, the first CRISPR-based genetic therapy, Casgevy, has also been approved for the treatment of these conditions.

In addition, researchers are exploring the use of CRISPR in the treatment of certain types of cancer by engineering immune system cells to fight tumors more effectively. The technology is also being investigated as a potential treatment for genetic disorders that cause blindness, as well as for heart disease and muscular degeneration.

4. What is the difference between CRISPR and traditional genetic engineering?

Traditional genetic engineering often relied on the random insertion of new genes into the genome, a process that could lead to unpredictable disruptions. In contrast, CRISPR technology enables targeted editing at a specific genetic site. This makes it possible to direct changes to an exact location, down to the level of a single DNA letter, significantly reducing the risk of unintended damage and increasing the likelihood of successful treatment outcomes.

5. Are there risks associated with CRISPR technology?

One of the main challenges associated with CRISPR is a phenomenon known as “off-target effects,” in which the system may mistakenly cut DNA sequences that resemble the intended target but are not identical to it. Such errors can lead to unwanted mutations. To address this challenge, researchers at Bar-Ilan University developed advanced monitoring tools such as CRISPECTOR, which make it possible to analyze the accuracy of gene editing and verify its safety before use in humans.

6. Is gene editing with CRISPR hereditary?

That depends on which cells are being edited. If the editing is performed in regular body cells (somatic cells), such as blood or liver cells, the change will affect only the patient and will not be passed on to future children. However, if the editing is performed in reproductive cells, such as sperm or egg cells, or in embryos at very early stages of development, the genetic change will be present in all the cells of the child’s body and may be inherited by future generations. This type of editing, known as germline editing, is the subject of intense ethical and legal debate and is heavily restricted in most countries around the world.

7. Why is CRISPR considered a scientific revolution?

CRISPR has made access to DNA editing far more accessible and practical for laboratories around the world. The ability to effectively “rewrite” the code of life has opened the door to true personalized medicine, allowing treatments to be tailored to the unique genetic profile of each individual and offering the potential to treat diseases that were once considered incurable.

At the same time, it is important to emphasize that CRISPR is not suitable for every disease or every patient. Its use depends on the type of genetic defect involved, the patient’s medical condition, safety considerations, and the stage of development of the treatment itself. For this reason, every medical application of CRISPR requires rigorous scientific and clinical evaluation.