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Revista Colombia Médica
Universidad del Valle - Facultad de Salud
ISSN: 0120-8322 EISSN: 1657-9534
Vol. 42, Num. 1, 2011, pp. 8-8
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EDITORIAL
Colombia Médica, Vol. 42, No. 1, January-March, 2011, pp. 8
EDITORIAL
GENOMIC MEDICINE
Ignacio Briceño Balcázar, MD, PhD
Professor, Universidad de la Sabana,
Full Professor, Pontificia Universidad Javerian
Code Number: rc11002
Until
the twilight of the 20th century, genetics was a branch of medicine
applied to diseases of rare occurrence. The advent of the human
genome sequence and the possibility of studying it at affordable costs
for patients and healthcare institutions, has permitted its application
in high-priority diseases like cancer, cardiovascular disease,
diabetes, and Alzheimer’s, among others.
There
is great potential in predictive and preventive medicine, through
studying polymorphic genetic variants associated to risks for different
diseases. Currently, clinical laboratories offer studies of over 30,000
variants associated with susceptibilities, to which individuals can
access without much difficulty because a medical prescription is not
required. These exams permit conducting a specific plan of preventive
medicine. For example, upon the possibility of finding a
deleterious mutation in the BRCA1 and BRCA2 genes, the patient can
prevent the breast cancer by mastectomy or chemoprophylaxis and in the
presence of polymorphisms associated to cardiovascular risk preventive
action may be undertaken through changes in life style (diet, exercise,
etc.).
Legal
aspects are also present in this new conception of medicine. For
example, currently there is legislation for medications to indicate on
their labels the different responses such medication can offer
regarding the genetic variants of the patients, given that similar
doses may provoke adverse reactions in an individual, while for another
such dosage may be insufficient. This scenario would allow verifying
the polymorphisms of drug response prior to administering medications
like anticoagulants, hyperlipidemia treatments, or chemotherapy, among
others.
We
must specially mention recessive diseases, produced by the presence of
two alleles of a mutated gene, which are inherited from the mother, as
well as the father. By studying the mutations, we may learn if a couple
is at risk of bearing children with the disease; thus, conducts may be
undertaken like selection of embryos or opting for adoption.
Although
genetic studies of molecular profiles are promissory, there are
questions on how these are requested and how the results are
communicated to the patients, their clinical use, application of the
pre-symptomatic diagnosis – especially in children, the bad
intended use of this information by medical insurance companies
considering pre-existing conditions, and finally, the great amount of
information and its application in populations where prior studies of
association have not been conducted may be cause for concern.
In
developed nations, these types of exams are requested without medical
prescription in pharmacies that mail the results directly to the
interested party. It is worrisome what can happen to patients
upon receiving this information; for example, if the report indicates
susceptibility to Alzheimer’s or cancer, without medical support
to identify the presentation risks and the possibility of transmitting
the disease to their offspring. This suggests the validity, more
than ever, of genetic counseling when delivering analysis results.
On
the other hand, insurance companies must consider molecular genetic
profiles as a preventive tool that permits improving service quality
while lowering costs; for instance, in cancer cases where prophylaxis
measures are notably less costly than treatment.
Another
aspect to bear in mind is that association studies of genetic
polymorphism and disease need thousands of cases and controls, making
them very costly for implementation in Colombia. For this reason, the
exams include the ancestral report for the purpose of interpreting the
results according to ethnic origin. For now, this is the most
adequate conduct considering that it will take a long time before
validation studies can be conducted.
As
with all great progress in medicine, genomics opens a path that will
bring enormous benefit inasmuch as the criteria for good medical
practices are considered.
Copyright 2011 - Colombia Médica
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