Fig. 2.

The human MHC paralogous regions differ significantly in size, with the CD1 genes in the middle of a large region on chromosome 1 relative close to paralogous genes, the classical class I genes on the edge of a small region on chromosome 6 very close to paralogous genes, and the FcRn gene relatively far away from one end of paralogous genes on chromosome 19. Comparison of the four paralogous regions based on the genes originally proposed by Kasahara (along with the FcRn or FCGRT gene, but with those deemed later to be questionable excluded), roughly to scale with the chromosomal position according to the current assembly of the human genome (GRCh38.p5). Circles indicate centromeres, thin lines indicate gene(s) considered to be paralogous (many tens to thousands of other genes not shown), and positions are given in megabases (Mb) according to EMSEMBL (www.ensembl.org/Homo_sapiens). Class I genes (red) (colour figure online)