Basics facts about gene therapy
The genes, small pieces of DNA that contain encoded information
about how to make proteins (they are some kind of 'blueprints'
for the body) are the basic units of human heredity. When, for
some reasons, something happens to the genes and they can't
perform their normal functions, gene therapy is required. Gene
therapy consists of several methods for 'repairing' the
defective genes, curing the diseases that are caused by them.
You can say that gene therapy 'cuts the evil from its seeds'.
As said before, gene therapy uses several methods for fixing the
broken genes. The most common of them is to replace the
defective genes with healthy ones. This is done using a molecule
that carries the healthy gene to the desired spot. These
molecules that gene therapy uses are usually modified viruses
that can carry the healthy gene. Depending of the type of
molecule that needs to be carried, several types of viruses are
used :
Adenoviruses - they can carry DNA fragments, and then they
infect the desired cells, putting the healthy DNA there. Gene
therapy treatment using adenoviruses must be repeated regularly.
Retroviruses - can carry RNA molecules. They introduce the RNA
inside the cells they infect, and also some enzymes. Then, the
RNA molecules produces copies of the healthy, required DNA.
This process is called reverse transcription.
Adeno - associated viruses - Gene therapy uses these viruses
because they carry single-chains of DNA and introduce them in
the 19th chromosome.
Herpex simplex viruses are also sometimes used, but gene therapy
doesn't only depend on carrier viruses - the normal DNA can be
directly inserted into the infected cells, but this method is
used quite seldom. Scientists are doing some experiments with
introducing artificial human chromosome inside the cells, but
this still presents some difficulties.
Gene therapy can surely be the future of medicine, and it could
replace traditional drug - based medicine, and it could easily
heal difficult diseases, but for many people it poses some
ethical and religious problems, so the whole thing is under a
big question mark.