Cardiovascular Journal of Africa: Vol 28 No 2 (March/April 2017)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017 80 AFRICA
We found five homozygous and 11 heterozygous mutations
in the MTHFR gene and the others did not have mutations.
Homozygosity for the C677T polymorphism of the MTHFR
gene predisposes individuals to CAD or DVT.
The A1/A2 polymorphism of the GpIIIa gene caused by
a T-to-C nucleotide substitution at position 1565, which is
associated with the occurrence of the amino acid Leu →Pro
variant at residue 33 of the mature protein,17 has been widely
studied in cardiovascular diseases.18 These studies have shown
that possession of an A2 allele increases the risk for MI,19,20
CAD,21 and restenosis after stent placement.22 Eight patients had
a GpIIIa gene polymorphism in our study.
PAI-1 is a major inhibitor of the fibrinolytic system. This
protein is under the control of the 4G/5G polymorphism of
the PAI-1 gene, which is characterised by the presence of five
guanine nucleotides in the promoter zone instead of four.
Carriers of the 4G/5G allele would be more at risk for CAD.22-25
We had 15 patients who had this polymorphism.
This study was limited by the small sample size and ethnicity
differences. Further exploration would be useful in future
studies, for which a larger sample size is needed.
Conclusion
This study demonstrates that the MTHFR C677T polymorphism,
and GpIIIa and PAI-1 genes are risk factors for CAD.
Considering that individuals who have homozygous mutations
in the MTHFR gene are prone to CAD in early adulthood, it
is possible that altered enzyme efficiency contributes to this
vulnerability. Genetic studies promise to revolutionise early
diagnosis, treatment and prevention of CAD and MI. A unique
advantage for the management of cardiovascular disease is that
a significant number of cases are potentially preventable. Early
diagnosis by genetic testing will force lifestyle modifications
in individuals with genetic risk factors, which alone or in
combination with other therapeutic options may delay the onset
of CAD or prevent MI.
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