Fig. 1.

(A) Partial alignment of the collagenous domain of MARCO highlighting residue 282. Humans possess a unique phenylalanine residue at residue 282, except those with the rs6761637 polymorphism, who possess the ancestral serine residue. For a list of species included in each group, see table 2. (B) The global minor allele frequency of rs6761637 (F282S) is 16.8% and varies in frequency between 3.6% in European to 34.5% in African populations. The F282S polymorphism is found at higher frequencies in East Asian (12.3%, n = 629), South Asian (18.6%, n = 657), and African (34.5%, n = 902) populations, relative to European (3.6%, n = 535) and Mixed American (4.8%, n = 468) populations. Each population is composed of multiple subpopulations (i.e., the Mixed American population is composed of Mexican Ancestry from Los Angeles, Puerto Ricans from Puerto Rico, Colombians from Medellin, Colombia, and Peruvians from Lima, Peru). Complete descriptions of each population are available in the 1000 Genomes project. (C) The rs6761637 SNP is in linkage disequilibrium with other polymorphisms associated with infection. Haplotype mapping illustrates that rs6761637 is in LD with four SNPs associated with susceptibility to pulmonary tuberculosis in the Chinese Han population (rs2278589, rs67517405, rs12998782, and rs17009726, n = 163) and one in the Gambian population (rs13389814, n = 179). No LD was observed between rs6761637 and the rs41279766 SNP from the European population (n = 535). All analyses were considered significant if P < 0.05. P values are available in supplementary table S1, Supplementary Material online.