In a population of 282 Caucasoid patients in end-stage renal failure (ESRF) Gm and Km typing has confirmed a significant increase in the frequency of the Gm1,2,17;21 haplotype. This was confined to an increase in the number of heterozygous Gm(1,2,3,17;21,5,10,13,14) individuals. A concomitant decrease in the frequency of presumptive Gm(3,5,10,13,14) heterozygotes was also confirmed. Analysis of individual renal diseases revealed significant immunoglobulin allotype, phenotype and haplotype frequency deviations in those patients presenting with hypertension, glomerulonephritis or pyelonephritis. The allotype distribution in patients with physical abnormalities of the urinary-genital tract, whether congenital or acquired, was normal.