Gene therapy was the
most prominent technique to alter genomic sequences to treat various diseases. But,
this technique was a random process which lacked accuracy and was prone to
cause unwanted mutations as well. Recently, a breakthrough in the field of
genetic engineering happened to occur in the form of a new technique named as
CRISPR technique, where CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. The technique is believed to be
potent enough to transform the ability of DNA experts to edit the genomes of
almost all living forms.
Scientists believe that
using this revolutionary technique, they will be able to engineer any part of
the human genome with extreme precision
and it will now be possible to make the most accurate and precise modifications
to any specific position on the DNA of the 23 pairs of human chromosomes without
introducing unwanted mutations.
The development of this novel technique is said to be hailed
as one capable of curing numerous chronic diseases ranging from cancers, HIV
infections, genetic disorders like Sickle cell anaemia, Down syndrome to even Huntington’s
disease.
It is believed that very soon this technique will be used in
gene therapy trials in humans and is expected to come up with phenomenal
results. Until now, gene therapy has largely relied on highly inaccurate
methods of editing the genome, often involving modified viruses that insert DNA
at random into the genome, which is too risky for many patients. But, the new method, transforms
genetic engineering because it is simpler and easy to edit any desired part of
the DNA molecule, even the individual chemical building-blocks or nucleotides
that make up the genetic alphabet.
Regarding this technique, Craig Mello of the University
of Massachusetts Medical School, who shared the 2006 Nobel Prize for
medicine for a previous genetic discovery called RNA interference, has
remarked, “Crispr is absolutely huge.
It's incredibly powerful and it has many applications, from agriculture to potential
gene therapy in humans.” He also added
that in addition to engineering the
genes of plants and animals, which could accelerate the development of GM crops and
livestock, the Crispr technique dramatically
"lowers the threshold" for carrying out "germline" gene
therapy on human IVF embryos. Germline gene therapy on sperm, eggs or
embryos to get rid of inherited diseases alters the DNA of all coming generations,
but fears over its safety, and the prospect of "designer babies", has
led to it being made illegal in Britain and many other countries.
In the initial stages, the Crispr process was identified as a
natural immune defence used by bacteria against invading viruses. Last year, a team
led by Jennifer Doudna at the University
of California, Berkeley,
published a seminal study showing that Crispr can be used to target any region
of a genome with extreme precision with the aid of a DNA-cutting enzyme called
CAS9.
The new gene-editing technique could address many of the
safety concerns because it is so accurate and it could then also be
applied to the germline, which indeed will relieve families and their future
generations from devastating genetic disorders.
This technique is a sure triumph in basic science and is a
tremendous breakthrough with huge implications in the field of molecular
genetics.
