Polygenic control of susceptibility to murine systemic lupus erythematosus.

Susceptibility to glomerulonephritis (GN) and anti-dsDNA autoantibody production was analyzed in crosses with a newly developed systemic lupus erythematosus-susceptible inbred strain, NZM/Aeg2410. The mode of inheritance and the number and location of systemic lupus erythematosus-associated susceptibility loci were analyzed by interval mapping in a backcross with C57BL/6. Three chromosomal intervals containing strong recessive GN susceptibility alleles were identified on chromosomes 1, 4, and 7, each containing several potentially interesting candidate genes. Heterozygosity at H-2 was also found to correlate strongly with GN susceptibility, consistent with previous findings in the NZB/NZW parental strain model. Logistic regression analysis indicated that each of these susceptibility alleles independently accounted for a component of GN susceptibility, and that susceptibility was inherited as a threshold genetic liability in this model system.