The analysis of anti-GM1, -GM2, -GM3, -GD1a, -GD1b, -GT1b, -GQ1b, IgG and IgM antibodies in patients with SLE, LN and control group, showed an interdependence between the modified sialylation of gangliosides and AGA synthesis rate in patients versus control. The gene discussed is AGA; the disease is systemic lupus erythematosus.