HLA-DQA1 and membranous glomerulonephritis: Genotypic and allelic frequency distributions for six single-nucleotide polymorphisms within PLA2R1 (rs4664308, rs3792189, rs3792192, rs1870102, rs17831251, and rs35771982) and one in HLA-DQA1 (rs2187668) were associated with morbidity of primary membranous nephropathy.