Biomedical Engineering Reference
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on the clinical presentation, the ECG pattern, and which gene is mutated. Genetic
testing offers the opportunity to exclude individual family members as mutation
carriers.
Following earlier studies of the involvement of some cardiac ion currents in
adverse drug interactions, recent reports have identified not only the ion channel
subunits involved but also a range of mutations and SNPs in ion channel genes that
predispose to both drug-induced and familial cardiac arrhythmia.
Polymorphism in the Angiotensinogen Gene
The renin-angiotensin system plays a central role in health and disease but the
determinants of renin-angiotensin system activity have not been fully elucidated.
A common variant of the angiotensinogen gene (T235) predicts elevated levels of
circulating angiotensinogen, and polymorphisms of this gene have been linked to
physiologic responses and to the risk of cardiovascular disease There is an associa-
tion between angiotensinogen M235T polymorphism and coronary artery disease
severity independently of other cardiovascular risk factors (Lanz et al.
2005
). T235
is also a genetic marker for early carotid atherosclerosis in a hypertensive popula-
tion, which has been shown to regression under antihypertensive treatment.
Kallikrein Gene Mutations in Cardiovascular Disease
All the components of the kallikrein-kinin system are located in the cardiac muscle,
and its deficiency may lead to cardiac dysfunction. Muations of the kallikrein gene
are associated with several diseases. In recent years, numerous observations
obtained from clinical and experimental models of diabetes, hypertension, cardiac
failure, ischemia, myocardial infarction, and left ventricular hypertrophy have sug-
gested that the reduced activity of the local kallikrein-kinin system may be instru-
mental for the induction of cardiovascular-related diseases. The cardioprotective
property of the angiotensin-converting enzyme inhibitors is primarily mediated via
kinin-releasing pathway, which may cause regression of the left ventricular hyper-
trophy in hypertensive situations. The ability of kallikrein gene delivery to produce
a wide spectrum of beneficial effects makes it an excellent candidate in treating
cardiovascular diseases (Sharma
2006
).
Kallikrein Gene and Essential Hypertension
Ten alleles with length and nucleotide sequence variations were identified in
the regulatory region of human tissue kallikrein gene. There are polymorphisms
in the regulatory region of human tissue kallikrein gene in the Chinese Han people.
Differences in both allele frequencies and genotype frequencies between these two
groups have provided evidence toward the association of hypertension with the
polymorphisms in this studied site (Hua et al.
2005
).
US Patent No. 5,948 from Medical University of South Carolina (Charleston,
SC) describes a biomarker for identifying a human subject as having an increased
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