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Explore the rich genetic and linguistic diversity in Africa and its implications for the design of large-scale genomic studies and fine mapping. Discover the African Genome Variation Project, which aims to study genetic variation in Africa to inform African genomics research. Learn about population structure, admixture, and differentiations across various African regions and ethnicities. Understand how this information can be leveraged in the study of African genomics and its implications for epidemiological studies and fine mapping.
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Population Structure and History in Sub-Saharan Africa Manjinder Sandhu
Why study genetic diversity in Africa? • Africa has the greatest genetic and linguistic diversity in the world • Genetic diversity has implications for the design of studies • Can large scale genomic studies be carried out across Africa? • Can we utilise population differentiation for fine mapping? • Can admixture mapping be used for certain traits?
What is the African Genome Variation Project? • Study of 16 ethno-linguistic groups across SSA from populations relevant to medical genomics • 100 individuals with dense (2.5M) genotype data in each • Largest diversity panel from Africa so far • Aim: to study genetic variation in Africa to inform large scale studies in African genomics
Eurasian cline YRI CEU
Khoe-San cline YRI Juhoansi
European and Khoe-San admixture in SSA South Africa Bantu Khoe-San West Central Africa West Africa North Africa East Central Africa East Africa K=2 K=3 K=4 K=5 K=6
Quantifying and dating admixture European admixture Khoe-San admixture
European and HG admixture in SSA Khoe-San admixture European admixture
Interpretation • Widespread European admixture in all SSA populations, dating to different time-points • Broadly consistent with demographic history • Hunter gatherer admixture seen in many SSA populations, particularly southern bantu populations • Dating consistent with the bantu expansion
How can this information be leveraged in the study of African genomics • Most populations used for epidemiological studies in Sub-Saharan Africa are not very differentiated • Differentiation seems to arise largely from admixture rather than divergence or drift • Implications for large-scale genomic studies and fine mapping
Next steps • Using admixture mapping of traits for phenotypically differentiated diseases between different populations • Understanding the relationship between admixture and LD structure in African populations in the context of fine mapping