Racial and genetic factors in IgA nephropathy.

Racial and ethnic variations in the incidence of IgA nephropathy (IgAN) could imply both genetic and environmental influences that exist in a complex and poorly understood interplay to modify the expression of the IgAN clinical phenotype. Progress in identifying genetic factors that influence either susceptibility to IgAN or its progression has been slow. Recent progress using family based approaches (genome-wide scan for linkage and family based genetic association studies) to study the genetic basis for susceptibility to familial and sporadic IgAN strongly point to clinical and genetic heterogeneity in the entity we presently call IgAN. The inconsistent findings reported from case-control genetic association studies may be explained by new understanding of the haplotype block structure of the human genome. Rapid improvements in available and developing technologies in the postgenomic era are needed and are expected to accelerate progress in understanding genetic factors underlying IgAN.