[Familial and hereditary mesangial glomerulonephritis with IgA deposits (author's transl)].

Idiopathic mesangial glomerulonephritis with IgA deposits was observed in two relatives, father and son, in a family of 5 members. In the father the disease started at age 43 with relapsing macroscopic hematuria, proteinuria, renal failure and hypertension, with a progressive course in the ensuing four years. The affected son, the oldest of three brothers, developed relapsing macroscopic hematuria at age 16; two years later renal function was normal and there was no hypertension, but microhematuria persisted without proteinuria. The mother and the other two brothers had no clinical or biological signs of renal disease. Serum immunoglobulins (IgG, IgA, and IgM) and complement (C3, C4, C3 proactivator) were normal in the patients and their relatives. Histocompatibility typing demonstrated the presence of HLA-Bw35 in the father and the two unaffected sons, being negative in the mother and the affected son. The analysis of HLA-Bw35 in 23 patients with IgA mesangial glomerulonephritis gave positive results in 30% of them, while the control group had a positivity of 15% (p non significant with the X2 test). The present observations suggest that IgA mesangial glomerulonephritis is a potentially familial and hereditary renal disease. HLA-Bw35 antigen appears not to be a genetic marker of the disease in our geographical area.