Cardiovascular Journal of Africa: Vol 26 No 2 Supplement (March/April 2015)

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S4 AFRICA
CVJAFRICA • Volume 26, No 2, H3Africa Supplement, March/April 2015
mortality has been accomplished by reducing population levels
of risk factors.8,9 A similarly dramatic decline in CVD mortality
resulting from population-level reductions of risk factors cannot
be demonstrated for sub-Saharan Africa for a variety of reasons.
First, reliable survey data on CVD risk factors and incidence
and mortality are virtually non-existent in sub-Saharan Africa
(SSA), with the exception of the Republic of South Africa,
Mauritius and the Seychelles.10 A recent meta-analysis of
sample surveys however documented the substantial burden of
hypertension, and the all-too-obvious low rates of treatment and
control.11 Likewise, as documented in three articles in this issue,
stroke imposes an enormous burden on the population of SSA.
Therefore, while the attempt is being made to drive biomedical
research forward into wholly unchartered territory through
the use of genomic technology, we must not lose sight of the
historical context of the evolution of CVD and the requirement
in the short run to use what we already know will spare patients
premature mortality, morbidity and misery.
For reasons too obvious to require elaboration, the
infrastructure of public health surveillance for CVD risk factors
and primary care systems that can provide long-term treatment
are missing in most of SSA. Establishing these essential
components of a healthcare system must therefore rank as the
most urgent priority.
How then can we situate the research agenda for genomics
and the H3 programme within the real-world context of SSA? As
noted above, this question weighed heavily on the minds of the
scientists and staff who designed H3Africa, and the White Paper
and other related documents provide insightful responses to this
question. Science is a broad social movement and consistent
improvement in the health and economic opportunity of any
country requires a vibrant scientific community.
H3Africa has clearly injected tremendous enthusiasm into the
biomedical community in Africa and has led to rapid intellectual
and technical advances in many areas of biomedicine. As
editorialists, we respond to the question ‘what role for genomics?’
not with skepticism but rather a plea for an appreciation of the
full breadth of scientific achievement now available to those
who work to reduce the burden of CVD, and a reminder that
we must never forget that curiosity and skepticism are co-equal
ingredients of the research process.
Progress into the translational sphere is already being made
and genomics has led to multiple breakthroughs in CVD
research in recent years. The discovery of genetic variants of the
gene coding for PCSK9 has led directly to a major new treatment
modality for hyperlipidaemia.12 Notably, the mutation underlying
this discovery was found in an Afro-origin population, where it
occurs at a frequency of 1–2%, and underscores the importance
of genetic research in the highly diverse societies of SSA.
Identification of a variant in APOL1 has greatly improved
our understanding of the excess rates of renal failure in Afro-
origin populations,13-15 again based on a mutation occurring
primarily in Africans. Genomic research is also generating
mounting evidence that levels of high-density lipoprotein
(HDL) cholesterol are not causally related to risk of CVD.16 If
fully verified, a demonstration of a non-causal role for HDL
cholesterol would have a major impact on the approach of
physicians to the treatment of serum lipid levels and re-direct
an enormous research effort away from drugs intended to raise
levels of this lipoprotein.
We are on the threshold of the discoveries of the molecular
mechanisms underlying CVD that can improve the life of
patients everywhere, and, although only on the threshold, we can
confidently say that the door has been unlocked. For instance,
what if in this process we were able to realise a stroke-free
generation of individuals living with sickle cell disease? 17 What
if we were able to identify genetic or bio-molecular targets that
help transform the outcomes of CVD? Compelling research
questions such as these must be part of the strategic visioning in
biomedical research over the next decade.17
Many opportunities for important discoveries of the
mechanism of disease in CVD will surely be found in Africa.
In the interim, however, we must endeavour to also implement
evidence-based interventions that are feasible, affordable and
appropriate to implement within the constraints of the SSA
setting for the prevention and control of cardiovascular diseases
in Africa. A priority among these interventions is those that
address hypertension, diabetes, unhealthy diet, physical inactivity
and tobacco use. Additionally, investments to improve the
systematic collection, analysis and reporting of survey data
on CVD incidence, prevalence, magnitude and trends in risk
exposure, disease burden and mortality will be necessary.
The current myriad of clinical and public health challenges
cannot await the promises of the genomic revolution. Active
dissemination and implementation of effective interventions
for prevention, treatment and control of CVD and other
non-communicable diseases must be prioritised. Herein, the
words of Dr Martin Luther King ring loud and true because
indeed ‘… we are confronted with the fierce urgency of now...
there is such a thing as being too late… this is a time for vigorous
and positive action.’
The views expressed in this article are those of the authors and do not neces-
sarily represent the views of the National Heart, Lung, and Blood Institute,
National Institutes of Health, or the US Department of Health and Human
Services.
References
1. Gabriel SB, Schaffner SF, Nguyen H, et al. The structure of haplotype
blocks in the human genome. Science 2002; 296(5576): 2225–2229.
2. McVean G, Spencer CC, Chaix R. Perspectives on human genetic varia-
tion from the HapMap Project. PLoS Genet 2005; 1(4): e54.
3. Abecasis GR, Auton A, Brooks LD, et al. An integrated map of genetic
variation from 1,092 human genomes. Nature 2012; 491(7422): 56–65.
4. Gurdasani D, Carstensen T, Tekola-Ayele F, et al. The African Genome
Variation Project shapes medical genetics in Africa. Nature 2015;
517(7534): 327–332.
5. National Institutes of Health. NIH and Wellcome Trust announce
partnership to support population-based genome studies in Africa. NIH
News 2010 June 22; Available at: URL:
.
6. Owolabi MO, Mensah GA, Kimmel PL, et al. Understanding the rise
in cardiovascular diseases in Africa: harmonising H3Africa genomic
epidemiological teams and tools. Cardiovasc J Afr 2014; 25(3): 134–136.
7. H3Africa Working Group. Harnessing genomic technologies
toward improving health in Africa: Opportunities and challenges.
Recommendations for the Human Heredity and Health in Africa
(H3Africa) Initiative to the Wellcome Trust and the National Institutes
of Health. National Human Genome Research Institute/National