The pathogenic mechanism that causes IgA nephropathy remains unknown, but accumulated evidence has led to the “four-hit hypothesis”, starting with an abnormal glycosylation pattern of IgA (galactose-deficient IgA1) manifested through increased levels of poorly O-galactosylated IgA1 (gd-IgA1) in blood circulation, which causes the production of circulating auto-antibodies and consequentially the formation and deposition of immune complexes in the mesangium [4,5]. Here, IGHA1 is linked to IgA glomerulonephritis.