Two gene loci and so four alleles exist. Epistatic variance involves an interaction between different alleles in different loci. The locus affects the expressed trait only through changing the expression of other loci. Genetic draft is the effect on a locus by selection on linked loci. There were 3 quantitative trait loci that explained most of the phenotypic variation. The system has 2 CRISPR loci and 9 Cas genes. The inheritance for both loci is autosomal dominant. There is considerable overlap between susceptibility loci for IBD and mycobacterial infections. Six genetic loci found by linkage are known and listed below. This is consistent with a heterozygous or balancing selection coefficient for these loci. Orthologues of the 4 loci have been mapped in various species. Many of the loci were previously uncharacterized. The bivariate iso-density loci plotted in the formula 66-plane are ellipses. Additionally they took 35 protein coding loci from databases. The second wave leads to demethylation of specific loci.