Frequency of PAR4 Ala120Thr variant associated with platelet reactivity significantly varies across sub-Saharan African populations

Abstract

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Figure 1.

Frequencies of the PAR4 rs773902 SNP in different world populations. (A) Allele frequencies in African and non-African populations, including those reported in the 1000 GP and HapMap projects as well as the Somali genotype data presented in this letter. (B) Continental frequencies of the A allele using populations reported in the 1000 GP and HapMap projects. The African panel is represented by 6 West African and 2 East African populations. Error bars represent relative standard deviation of the mean. (C) The 18 regions of the Somali republic. Birthplaces (ie, provinces of birth) of the study participants are highlighted in green. AFR, African; AMR, admixed American; EAS, East Asian; ESN, Esan in Nigeria; EUR, European; IBS, Iberian population in Spain; ITU, Indian Telugu from the United Kingdom; KHV, Kinh in Ho Chi Minh City, Vietnam; MKK, Maasai in Kinyawa, Kenya; PEL, Peruvians from Lima, Peru; SAS, South Asian; SOM, Somalis in Puntland, Somalia; YRI, Yoruba in Ibadan, Nigeria.

Figure 2.

Haplotype and heterozygosity variations for populations in different continents using a 100-kbp region on chromosome 19 encompassing the PAR4 gene (F2RL3). (A) Snapshot viewing the region examined, which encodes 3 genes including F2RL3, utilizing the University of California Santa Cruz genome browser. The F2RL3 gene (3747 base pairs) is highlighted in red. (B) Continental haplotype plots. Rows and columns represent haplotypes and SNPs, respectively. Haplotypes of the same color are identical. The complexity of African haplotypes (shown here as denser and richer mosaics) is a result of haplotype diversity and lower degree of linkage disequilibrium. (C) Heterozygosity scores for European populations. Dashed lines denote subpopulations; solid line represents the average (all). For European populations, combined heterozygosity scores for Caucasians are also included. Horizontal axis shows position of chromosome 19, and vertical axis represents heterozygosity (hzy). European populations included are: Adygei (purple), Basque (blue), Sardinian (green), and Caucasian (red). (D) Heterozygosity graph similar to that shown in panel C for African populations, including San (blue), Pygmy (red), and Bantu (green). Note the higher heterozygosity variation in African populations compared with Europeans.