Bantu CNV Dataset

Copy number variations (CNVs) account for a significant proportion of inter-individual genomic variation. However, a majority of genomic variation studies have focused on single nucleotide variations (SNVs), with limited genome-wide analysis of CNVs in large cohorts, especially in populations that are under-represented in genetic studies including people of African descent. In this study, we carried out a genome-wide CNV analysis in > 3400 healthy Bantu Africans from Tanzania using high density (> 2.5 million probes) genotyping arrays. We identified over 400,000 CNVs larger than 1 kilobasepairs (kb), for an average of 120 CNVs per individual. Notably, we detected 4,823 CNVs in this cohort, which have not been reported previously. Further, we detected 866 large CNVs (> or =300 kb), which overlapped with genomic regions associated with multiple congenital anomaly syndromes, including Prader-Willi/Angelman syndrome (Type1) and 22q11.2 deletion syndrome. Furthermore, several of the common CNVs seen in our cohort (> or = 5 %) overlap with genes previously associated with developmental disorders. These findings may help to refine the phenotypic outcomes and penetrance of variations affecting genes and genomic regions previously implicated in diseases, mainly in people of European descent. Our study provides one of the largest datasets of CNVs from individuals of African ancestry, enabling improved clinical evaluation and disease-association of CNVs observed in research and clinical studies in African populations.