Although the genetics play a fundamental role in personalized medicine, the role
of epigenetics should not be ignored.^34 Recently, GWAS was run in parallel with a
meta-analysis of methionine metabolism to identify the impact of epigenetic path-
ways in stroke risk.^35 In contrast to simple genetics based on changes in the DNA
sequence, epigenetics refers to gene regulation changes caused by mechanisms that
do not involve nucleotide sequence modification but other changes, such as DNA
methylation and histone modification. Epigenetic changes are known to be
connected with an increased risk of common diseases, such as cardiovascular
diseases, cancer, dementia, and others. The results of Williams et al. ( 2014 )^36
have shown actually the association of different genes involved in the folate one
carbon metabolism pathway (and thus related to methionine metabolism) with the
incident of stroke, and the data emphasized the regulators of the pathway as
potential therapeutic targets.
2.4 Can Identifying Genes for Stroke Help Patients?
Unfortunately, very recent studies on the possibility to predict stroke through
genetic risk functions^37 have concluded that the SNPs associated with stroke and
its risk factors result only in a small improvement in the prediction of future stroke
compared with the classical epidemiological risk factors. The identified genetic
variants in genes related to predisposition to stroke explain only a small proportion
of overall stroke risk and therefore are not currently useful in predicting risk for the
individual patient, and the clinical use of genetic profiling of stroke risk is likely to
be some way in the future.^38
In the more immediate future, identifying novel genetic variants may open the
possibilities for pharmacogenomics, which is trying to predict specific drug response
and the potential for adverse effects in each patient. Although pharmacogenomics
still does not have a great impact on routine clinics, two potential applications in
tailoring antiplatelet therapy in patients with cerebrovascular diseases, including
stroke, have been proposed, for the drugs clopidogrel and warfarin.^39
Probably the most important result of the identification of novel genetic variants
related to stroke is the discovery of new molecular and cellular pathways involved in
the etiopathogenesis of the disease. The basic understanding of systems and mecha-
nisms involved in normal and deviant functioning of the CNS is essential for the
development of new therapies for stroke and other diseases and disorders of the brain.^40
(^34) Ozomaro et al. ( 2013 ) and Schierding et al. ( 2014 ).
(^35) Williams et al. ( 2014 ).
(^36) Williams et al. ( 2014 ).
(^37) Ibrahim-Verbaas et al. ( 2014 ) and Malik et al. ( 2014 ).
(^38) Ozomaro et al. ( 2013 ) and Markus ( 2012 ).
(^39) Markus ( 2012 ).
(^40) Editorial ( 2013 ).
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