To build a resource that greatly expands Alzheimer’s disease genetic studies in the currently underrepresented African ancestry populations and Hispanic/Latinx groups, the John P. Hussman Institute for Human Genomics (HIHG) at the University of Miami Miller School of Medicine, USA will collaborate with the College of Medicine, University of Ibadan (CoMUI) which leads institutions in 9 African countries in a major five-year, international, multi-site initiative titled the “Recruitment and Retention for Alzheimer's Disease Diversity Genetic Cohorts in the Alzheimer’s Disease Sequencing Project (READD-ADSP)”. This collaborative study involves five U.S. sites and ten country lead sites across Africa.
The College of Medicine University of Ibadan is the African Coordinating Center and leads other African institutions under the aegis of the African Dementia Consortium (AfDC). The institutional country leads across Africa include the College of Medicine, University of Ibadan; the University of Ghana College of Health Sciences/Korle-Bu Teaching Hospital Accra, Ghana; Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Makerere University, Kampala, Uganda; University of Parakou, Parakou, Benin; University of Yaounde, Yaounde, Cameroon; University of Nairobi, Nairobi, Kenya; Eduardo Mondlane University, Maputo, Mozambique; Kilimanjaro Christian Medical College, Moshi, Tanzania; and Addis Ababa University, Addis Ababa, Ethiopia. The Nigerian collaborative group includes 4 other sites in Nigeria —College of Medicine, University of Lagos; University of Ilorin; Neuropsychiatric Hospital, Aro, Abeokuta and Ahmadu Bello University, Zaria.
This new initiative is funded by a $46 million grant awarded to the HIHG by the National Institute on Aging, part of the National Institutes of Health. Professor Margaret A. Pericak-Vance, Ph.D., director of the HIHG and Dr. John T. Macdonald Foundation Professor of Human Genetics, will oversee the overall efforts of the principal investigators across several domestic and international sites.
Led by Dr. Rufus Akinyemi, M.B., B.S., Ph.D., F.M.C.P., (Principal Investigator, African sites) and Professor Adesola Ogunniyi, M.B., Ch.B., MD, F.M.C.P.,(Co-Principal Investigator, African sites), the AfDC is a coalition of African dementia researchers in a multidisciplinary framework, working together with the aim of generating clinical, cognitive, socioeconomic, neuroimaging, genomic, and biomarker data to improve the phenotypic characterization of dementia, particularly Alzheimer’s, in Africa. The AfDC’s goals include the translation of scientific evidence to health policy and clinical practice, lessening the burden of dementia among Africans and ultimately contributing to the reduction of the global burden of dementia. Currently the AfDC includes researchers from nine African countries namely Nigeria, Ghana, Uganda, Benin, Cameroon, Kenya, Mozambique, Tanzania, and Ethiopia.
Alzheimer’s is a complex disease with a pronounced genetic component; its estimated heritability is 60% to 80%. Though the disease can affect individuals of almost all ethnic and ancestral backgrounds, efforts for genetic studies have not historically been well diversified. Most genetic-based studies in Alzheimer’s disease have been performed in non-Hispanic white populations of European ancestry, with little participation from indigenous Africans.
The new multi-site enterprise will help to bridge the research disparities that have historically existed in diverse communities. Through the recruitment, assessment, and genetic analysis of a significantly large cohort of participants of African and Hispanic/Latinx ancestries, clinical, phenotypic, and genetic data, along with social determinants of health factors will be collected to create a large genomic study resource.
The cohort will include 5,000 individuals from various African countries, 4,000 African Americans, and 4,000 Hispanic/Latinx individuals. Data collected from participants will be added to existing databases of harmonized data from other ongoing studies as part of the Alzheimer’s Disease Sequencing Project (ADSP).
Recruitment in Africa will be done under the umbrella of the AfDC. This new initiative is particularly significant because members of African American and Hispanic/Latinx communities have one of the highest risks of developing AD. Thus, identifying the ancestral differences in causes of Alzheimer’s disease is critical to treating all individuals.
“We recognized early on the need to advance community-based participatory efforts to increase understanding of Alzheimer’s disease,” said Dr. Pericak-Vance. “Only by being inclusive in our approach and including all groups will we be able to develop targeted drug therapies, which would be universally beneficial.”
“These studies will accelerate our understanding of the genetic factors contributing to Alzheimer’s disease, especially in the multi-ancestral population of the United States as well as populations around the world,” said Jeffery Vance, M.D., Ph.D., Professor of human genetics and neurology, HIHG.
“Inclusion of indigenous Africans in this large Alzheimer’s disease genomic study is timely with huge potentials to better understand the genetic architecture of the disease, unmask new causal variants, develop Afrocentric polygenic risk score and accelerate the discovery of new treatments” said Dr. Rufus Akinyemi, a senior research fellow/consultant neurologist in neuroscience, genetics and neurology at the University of Ibadan College of Medicine/University College Hospital, Ibadan, Nigeria.
Studies show that people differ genetically based on their ancestral backgrounds when it comes to Alzheimer’s risk. Therefore, the participation of the African and Hispanic/Latinx ancestries is essential in the search for possible causes, treatments, and solutions specific to these groups and more broadly applicable to all people with Alzheimer’s.
Through the participation of individuals, the initiative will be able to help address inequalities and medical disparities in Alzheimer’s treatment and prevention. The study is also one of the first to examine the interaction between ancestry and the social determinants of health. Both factors can contribute to the risk and age of onset of Alzheimer’s disease and studying both types of risk factors will help researchers understand how they interact in the development of Alzheimer’s.
For more information, or to participate in the study, please contact AfDC country lead co-investigators or visit www.READD-ADSP.org (live August 1, 2022).