Gene editing is emerging as a significant force in scientific progress, although the possibilities depicted in Jurassic Park remain beyond current reality.
Altering the genetic information that determines human identity is already influencing medicine, offering new approaches to conditions previously regarded as incurable.
The technology is also being applied to crop development, with scientists seeking plants that withstand pests and disease more effectively.
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats.
Its full name may be difficult to pronounce, but its capabilities could transform several areas of science.
The system was identified in the late 1980s and comprehensively described during the following decade.
Emmanuelle Charpentier and Jennifer Doudna later established it as a programmable method for changing genes, earning the 2020 Nobel Prize in Chemistry for their work.
The mechanism originated in bacteria as part of their defence against bacteriophages, the viruses that infect them.
Specialised sections known as spacers are stored within CRISPR sequences and act as a cellular record of previous infections.
Each spacer contains genetic material captured from a virus that previously attempted to invade the bacterium.
Two proteins, Cas-1 and Cas-2, are central to how that record is created.
They remove a section of invading bacteriophage DNA and place it within the CRISPR sequence for preservation.
This process resembles the way the human immune system retains knowledge of earlier infections, although the bacterial mechanism operates at a much smaller scale.
When the same bacteriophage returns, the corresponding spacer is converted into guide RNA.
This guide consists of spacerRNA, derived from the stored viral DNA, and tracrRNA, which helps it connect with the cutting protein.
It then joins Cas-9, an enzyme containing nuclease activity that severs foreign DNA into two sections, neutralising the invader rather than incorporating it into the bacterial genome as Cas-1 and Cas-2 do.
Researchers found that the guide did not have to consist of material acquired from a bacterial immune response.
In 2012, Charpentier and Doudna demonstrated while working with Streptococcus pyogenes that two guide RNAs could be combined and altered to direct Cas-9 towards a selected DNA sequence.
The bacterial defence system could therefore be adapted as a gene-editing instrument.
Cutting DNA is only the first stage of the process.
Cells attempt to reconnect the divided strands, and errors during this repair can introduce small mutations that disable the intended gene.
Researchers can instead provide a template containing the required DNA, enabling new genetic material to be inserted into the genome and the genetic code to be reprogrammed.
CRISPR-based treatment has already achieved clinical success against sickle cell disease.
This inherited blood disorder is linked to a gene coding for a component of haemoglobin and causes blood cells to take on a sickle-like shape.
Its symptoms include joint pain, weakness, and swelling of the hands and limbs.
NICE approved a new therapy for NHS use in England in January 2025 for patients aged 12 or older with severe cases.
In July of the same year, the FDA approved that drug for use in the USA as the first and only genetic therapy authorised for children from the age of two.
It covers both sickle cell disease and a particular form of beta thalassemia.
Rollouts are also planned in several other major European countries.
Prime editing represents another area of development.
Unlike methods that cut both strands, it affects only one and uses a tailored guide containing a replacement sequence.
This permits short sections of DNA to be rewritten with fewer unintended alterations.
The approach has produced promising results in the in vivo treatment of Wilson’s disease, where it acts on liver-cell DNA to remove a mutation responsible for excessive copper accumulation in the body.
Technical difficulties remain.
Genetic changes may occur at sites other than their intended target, producing off-target effects, while the delivery mechanism must reach the appropriate body tissues safely.
Ethical debate also continues around the boundaries of human modification.
Possibilities raised by CRISPR include designer babies and, potentially, genetically enhanced super humans, as highlighted by the He Jiankui affair.
The technology has advanced rapidly over the fifteen years since its discovery.
Its journey from a bacterial protection mechanism to a clinical treatment demonstrates its significance, although its future will depend on rigorous testing, patience and societal decisions about how such power should be handled.
The central issue extends beyond whether CRISPR can be used to the question of whether its application should proceed, a concern echoed by Dr Ian Malcolm’s warnings in the 1993 film.