Hereditary nephritis: a re-examination of its clinical and genetic features.

In order to re-evaluate current concepts of hereditary nephritis we studied the urinary findings, the course of the disease, and its genetic transmission in two large pedigrees. We identified 150 patients with hereditary nephritis. Our data show that microscopic hematuria is the most reliable urinary criterion for diagnosing hereditary nephritis in both male and female patients. The hematuria is frequently accompanied by erythrocyte casts indicating that the renal lesion is a glomerulitis. Men are more severely affected than women. They have striking urinary abnormalities, which are present in early childhood, and they progress to renal failure in adult life. Affected women have less obvious urinary abnormalities and rarely develop uremia. In these two families a sex-linked dominant mode of genetic transmission was present. The demonstration that hereditary nephritis is X-linked, at least in some families, helps to explain the difference in severity between men and women and the variable expression among affected women.