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

41 / 64

AFRICA S39
CVJAFRICA • Volume 26, No 2, H3Africa Supplement, March/April 2015
Stroke genomics in people of African ancestry:
charting new paths
RO Akinyemi, B Ovbiagele, A Akpalu, C Jenkins, K Sagoe, L Owolabi, F Sarfo, R Obiako, M Gebreziabher,
E Melikam, S Warth, O Arulogun, D Lackland, A Ogunniyi, H Tiwari, RN Kalaria, D Arnett, MO Owolabi,
for the SIREN investigators as members of the H3Africa Consortium
Abstract
One in six people worldwide will experience a stroke in his/
her lifetime. While people in Africa carry a disproportionately
higher burden of poor stroke outcomes, compared to the rest
of the world, the exact contribution of genomic factors to
this disparity is unknown. Despite noteworthy research into
stroke genomics, studies exploring the genetic contribution to
stroke among populations of African ancestry in the United
States are few. Furthermore, genomics data in populations
living in Africa are lacking. The wide genomic variation of
African populations offers a unique opportunity to identify
genomic variants with causal relationships to stroke across
different ethnic groups. The Stroke Investigative Research and
Educational Network (SIREN), a component of the Human
Health and Heredity in Africa (H3Africa) Consortium, aims
to explore genomic and environmental risk factors for stroke
in populations of African ancestry in West Africa and the
United States. In this article, we review the literature on the
genomics of stroke with particular emphasis on populations
of African origin.
Keywords: stroke, cerebrovascular risk factors, genomics, genet-
ics, Nigeria, Ghana, Africa, African ancestry
Cardiovasc J Afr 2015; 26: S39–S49
DOI: -2015-039
Stroke is the clinical culmination of several complex processes
and interacting pathways that involve various genetic and
environmental factors.1 However, the exact nature and level of
the contribution of genetic factors to stroke and its different
subtypes have not been clearly established. Presumably, genetic
contributions to stroke may result from common variants
with small effect sizes, rare variants with large effect sizes,
or a combination of both.2-4 Nevertheless, studies exploring
the genetic underpinnings of the peculiarities of stroke in
populations of African ancestry in the United States are few,3,5-7
while there are hardly any data on populations living in Africa.
The diverse genomic variation of African populations8-10 offers
a unique opportunity to identify novel genes and molecular
pathways of stroke that may lead to new and better prevention
and treatment options for stroke in people of African ancestry
and other global populations. Understanding the interplay of
genetic and environmental risk factors for stroke is critical to
the prediction of its occurrence, severity and outcome as well as
the formulation of successful tailored treatment and prevention
programmes. In addition, the biology of stroke subtypes will be
better deciphered.
In this review article, we provide an overview of the changing
global and in particular, African epidemiology of stroke, the
known peculiarities of stroke in Africa, extant literature on
the genomics of stroke and cerebrovascular risk factors, with
particular attention to people of African ancestry, as well as
opportunities for charting new paths through the Human,
Health and Heredity in Africa (H3Africa) initiative.11,12
Division of Neurology, Federal Medical Centre Abeokuta,
Nigeria
RO Akinyemi, MB BS, PhD
Department of Neurosciences, Medical University of South
Carolina, USA
B Ovbiagele, MD, MSc
M Gebreziabher, PhD
S Warth, BSc
D Lackland, PhD
College of Health Sciences, University of Ghana, Accra,
Ghana
A Akpalu, MB BS
K Sagoe, PhD
Department of Medicine, Bayero University, Kano, Nigeria
L Owolabi, MB BS
School of Medical Sciences, Kwame Nkrumah University of
Science and Technology, Kumasi, Ghana
F Sarfo, MB BS, PhD
Department of Medicine, Ahmadu Bello University, Zaria,
Nigeria
R Obiako, MB BS, MSc
Department of Public Health, University of Alabama at
Birmingham, USA
H Tiwari, PhD
D Arnett, PhD
Institute of Neuroscience, Newcastle University, UK
RO Akinyemi, MB BS, PhD
RN Kalaria, PhD, FRCPath
College of Medicine, University of Ibadan, Ibadan, Nigeria
E Melikam, MSc
O Arulogun, PhD
A Ogunniyi, FRCP
MO Owolabi, MB BS, DM,