[HLA-DQ region and TCR gene polymorphism associated with primary IgA nephropathy in Japanese children].

We have investigated associations between HLA-DQ beta and TCRC beta gene polymorphisms and IgA nephropathy in Japanese children. DNA from 33 cases of IgA nephropathy, 29 cases of nephrotic syndrome and 29 cases of healthy volunteers were analyzed by Southern blotting using HLA-DQ beta and TCRC beta probes. A 2 kb (Taq I) polymorphic band that hybridized to the DQ beta probe was predominant in patients of IgA nephropathy (p < 0.05) compared to the controls. The 10 kb (Bgl II) polymorphic band of TCRC beta was also predominantly present (but not significantly) in the DNA of these patients. Proteinuria in IgA nephropathy patients was found to be associated with this 10 kb TCR polymorphism. We conclude that the HLA-DQ beta and TCR genes make major contributions to the genetic pathogenesis of IgA nephropathy in Japanese children.