However, abnormalities in the process of galactosylation of IgA1 will lead to the formation of poorly O-galactosylated IgA1 (also referred to as galactose-deficient IgA1, or Gd-IgA1), which can induce the production of anti-Gd-IgA1 antibodies, this is considered to be the initiating factor for IgA nephropathy (18). The gene discussed is IGHA1; the disease is IgA glomerulonephritis.