DNA copy number variations – Do these big mutations have a big effect on cardiovascular risk?
- Authors: Prestes, Priscilla , Maier, Michelle , Charchar, Fadi
- Date: 2019
- Type: Text , Journal article , Editorial
- Relation: International Journal of Cardiology Vol. 298, no. (2019), p. 116-117
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- Description: In simple terms, copy number variations or CNVs are replications or deletions in the DNA which, in humans, changes it from the normal number of two gene copies. These CNVs are caused by inherited or de novo structural changes such as duplications, insertions or deletions of repeated portions of genetic material (Fig. 1). These duplications can vary from one to ten or more copies and range in size from 50 DNA base pairs to several million [1]. Since their discovery in 1987 by Nakamura et al. [2], when they were initially named variable number tandem repeats, many studies have investigated their association with rare and common human diseases. Throughout evolution, some of these changes in copy number were beneficial such as the globin gene number duplication, while others such as the CNVs that cause Huntington's disease were not. In 2004, two landmark studies by Iafrate et al. [3] and Sebat et al. [4] found that large-scale copy-number variations, ranging in size from 100 kb to 2 Mb are common throughout the human genome, and that a high proportion of them are in known genes. These findings roused several association studies between CNVs and disease
Dysregulation of c-kit expression parallels the development of spontaneous genetic cardiac hypertrophy
- Authors: Marques, Francine , Prestes, Priscilla , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
- Date: 2015
- Type: Text , Conference paper
- Relation: Cardiac Society of Australia and New Zealand Annual Scientific Meeting and the International Society for Heart Research Australasian Section Annual Scientific Meeting; Melbourne, Victoria, Australia; 13th-16th August 2016; published in Heart, Lung and Circulation. Vol. 24, p. S401-S401
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- Description: Objective: The molecular processes associated with cardiac hypertrophy independent of blood pressure are still largely unknown. The hypertrophic heart rate (HHR) is normotensive and born with a reduced complement of cardiomyocytes that predisposes to cardiac hypertrophy and failure in later life. We investigated the expression of c-kit gene, a marker of cardiac stem cells and myocardial regeneration that could contribute to hypertrophy. Methods: Left ventricular c-kit mRNA expression was measured by real-time PCR in HHR and control strain in neonatal and 38-week old rats (n=7-12/group). We tested for linkage of c-kit expression with neonatal cardiac size in 197 second generation crosses (F2) of HHR and control strain. Results: c-kit mRNA was slightly up-regulated in neonatal (fold change +1.3, P=0.02) and markedly so in 38-week old HHR (+35.5, P=0.0003). Cardiac weight index was positively correlated with neonatal myocardial c-kit mRNA in the F2 population (r=0.19, P=0.007). Conclusions: In HHR hearts c-kit expression appears increased throughout life, but more so in the adult where cardiac hypertrophy is established and leading to failure. In aged hypertrophic hearts, over-expression of c-kit is likely a compensatory mechanism of the failing heart. Previous studies showed an activation of cardiac stem cells in the hypertrophic myocardium. Our study suggests that c-kit might be involved from an early age in mechanisms that lead to cardiac hypertrophy in adulthood.