Genome
editing enable scientists to remove or add genes or alter the genome of an
individual. This allows the treatment of diseases that are determined
by certain genes. Several methods are available for genetic editing, the most
recent being
CRISPR/Cas9 system.
‘Genetic modification of hereditary genes could soon be a reality!’
Human genome editing is
currently being tested in clinical trials only for treatment of genetic
diseases that are not inherited. One of the conditions that is being evaluated
is the treatment of advanced cancer in patients who do not respond to
radiotherapy or chemotherapy.
Gene
therapy is also being tried out
in conditions like hemophilia B and mucopolysaccharidosis I.
It is being tried out for the prevention
and treatment of disease and disability in which the benefit extends only to
the individual undergoing the treatment and does not affect subsequent
generations. As of now, it is not used for enhancements of physical or
mental abilities.
The
ethical implications of genome editing to edit heritable genes are much more
complex.
The side effects of this technique, if any, could extend through generations.
On the other hand, once people realize it's benefit, there is always a
risk that it could be misused for improving one's looks, or even producing
"perfect" babies.
At
the same time, the beneficial implications of genome editing of hereditary
genes cannot be ignored. If parents have defective genes that can
result in a serious disease in the baby, it can save several generations from
diseases that could be traumatic for the patient as well as the families, and
allows the baby to live a normal life. Therefore, experts from the National
Academy of Sciences and the National Academy of Medicine put down criteria that
would be required before clinical trials on genome editing of hereditary genes
can be allowed.
The genome editing of
heritable genes will have to be done in the sperm, ovary or the early embryo or
the precursor cells. There is still some time before it can enter
clinical trials. Some of the suggestions put forth by the experts regarding
clinical trials for editing hereditary genes are:
- It should be done
for genetic disorders for which no other reasonable alternatives are
available for their treatment
- It should be used
only for serious genetic conditions that have been proved without a doubt
to be caused by the genetic defect. Adequate oversight mechanisms should
be available to make sure that it does not extend to non-serious
conditions. It should not be used for enhancements at present time, and
public input and discussion would be needed before it is allowed.
- There should be
credible preclinical and /or clinical data to prove it's benefits and also find out the
risks
- There should be a
follow-up over multiple generations, since it will have implications in the
successive generations
- There should be
continuous assessments of the health as well as the social aspects along
with inputs from public
The experts also advise
that adequate transparency should be maintained and be available to patients,
their families and other persons involved in the process. At the same time, the
dignity of the person should be recognized and their decisions should be
respected.
Though there may come a
time when gene editing may be used or misused to achieve physical or mental perfection,
it must be remembered that everything need not be perfect. In fact, the
imperfectness in the world is what makes it more varied and beautiful.
Reference:- With Stringent Oversight, Heritable Germline Editing Clinical Trials Could One Day Be Permitted for Serious Conditions; Non-Heritable Clinical Trials Should Be Limited to Treating or Preventing Disease or Disability at This Time - (http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=24623)
Source-Medindia
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