IgA nephropathy (IgAN) is the most common form of primary GN and an important cause of kidney failure. Characteristically, patients with IgAN have increased serum levels of undergalactosylated IgA1 (gd-IgA1). To assess the degree to which serum gd-IgA1 levels are genetically determined in healthy individuals, we determined serum IgA and gd-IgA1 levels by ELISA in a sample of 148 healthy female twins, including 27 monozygotic and 47 dizygotic pairs. Using the classic twin model, we found the heritability of serum gd-IgA1 and IgA levels to be 80% (95% confidence interval, 66% to 89%) and 46% (95% confidence interval, 15% to 69%), respectively. These data indicate that serum gd-IgA1 levels are highly heritable. Elucidating the genetic basis of this heritability will be important in understanding the pathogenesis of IgAN.
Keywords: IgA nephropathy; gd-IgA1; glycosylation; human genetics.
Copyright © 2016 by the American Society of Nephrology.