While genetic variation in PLA2R1 exclusively associated with MN across 19 CKD aetiologies, the HLA-DQA1 risk allele was also associated with lupus nephritis (P = 2.8 × 10<sup>-6</sup>), type 1 diabetic nephropathy (P = 6.9 × 10<sup>-5</sup>) and focal segmental glomerulosclerosis (P = 5.1 × 10<sup>-5</sup>), but not with immunoglobulin A nephropathy.
Therefore, we have determined DQA1 alleles and re-examined DQB1 alleles in British Caucasoids with IgAN using an approach that can differentiate between the common DQ alleles; we have also extended our studies to Caucasoid populations from Northern and Southern Europe, thereby addressing the possibility of variation in genetic susceptibility between populations.