Familial IgA nephropathy. Evidence of an inherited mechanism of disease.

The evaluation of familial glomerulonephritis in patients with IgA nephropathy who were from central and eastern Kentucky resulted in the discovery of potentially related pedigrees containing 14 patients. An additional 17 members of the pedigrees had clinical glomerulonephritis, and 6 had "chronic nephritis" noted on their death certificates. Six patients with IgA nephropathy had a common ancestor. In addition, both parents of six patients with the disease came from families with other cases of IgA nephropathy. No single HLA haplotype or antigen was found in all the patients with IgA nephropathy. Our data on these pedigrees strongly support an inherited mechanism in the pathogenesis of IgA nephropathy in some patients.