Fig. 1: Fine-scale population structure in the healthcare delivery system reflects the geographical locations of the sample sources.
From: South Asian medical cohorts reveal strong founder effects and high rates of homozygosity
UMAP was run on all samples using the first 15 principal components. a In the South Asian subset, samples cluster into three major groups by sample origins: Pakistan, South India, and West Bengal and Bangladesh. The X-axis (UMAP1) was flipped so that the similarity between the graphical position of the three populations and the map of South Asia was apparent. b, c Samples with detailed locations or self-reported group memberships are shown to segregate within Pakistan and South India clusters. Among the samples from Pakistan and South India, some segregate with recent immigrants (e.g., Bengalis and Gujaratis) and historical immigrants (e.g., Lambadas), reflecting the metropolitan nature of the recruitment centers. d Samples from Birbhum District, West Bengal, have detailed self-reported group membership information. Upper castes, scheduled castes, and scheduled tribes clearly segregate, reflecting the historical reproductive isolation between these groups. Bayen and Santhal are two notable population isolates. e ADMIXTURE analysis of samples from the Birbhum District shows four major components. Labels are self-reported group identities with “general” denoting a lack of specified identity. PKN Pakistan, BLR Bangalore, MAA Chennai, COI Coimbatore, BAN Bangladesh, BRB Birbhum District, West Bengal, LAM Lambada. For other 3-letter codes, see Supplementary Data 1.
