Causes of immunoglobulin a nephropathy
The etiology of IgAN is unknown in the majority of cases.
There appears to be a dysregulation of the mucosal-type IgA immune response that results in the production of the aberrant IgA1. The aberrant IgA1 forms immune complexes that deposit in the glomerulus, although the specific relationship between the complexes glomerular deposition and injury remain incompletely understood.
It is likely that there are contributions from both genetic and environmental factors that cause the production of aberrant IgA1.
In familial IgAN, genetic linkage studies have suggested some specific genetic abnormalities.
Most of the reported kindreds with IgAN are inherited in an autosomal-dominant pattern with incomplete penetrance.
Genomewide association studies that include populations of IgAN from across the world have identified associated variants in the HLA gene family.
Associations have described abnormalities within 1q32 that contains multiple complement regulatory genes as a possible IgAN susceptibility locus.
In most cases, especially the more common sporadic variants, additional environmental factors are necessary to produce the clinical phenotype.