What is hereditary nephritis?

➢ Hereditary nephritis refers to a group of glomerular diseases caused by mutations in genes encoding GBM proteins. ➢ The most common of these rare diseases are Alport syndrome and thin basement membrane disease. ➢ In Alport syndrome, nephritis is accompanied by sensorineural deafness and various eye disorders, including lens dislocation, pos- terior cataracts, and corneal dystrophy. ➢ Thin basement membrane disease is the most common cause of benign familial hematuria with no systemic manifestations. Pathogenesis: ➢ The GBM is composed largely of type IV collagen, which is made up of heterotrimers of α3, α4, and α5 type IV collagen. ➢ This form of type IV collagen is crucial for normal function of the lens, cochlea, and glomerulus. ➢ Mutation of any one of the α chains results in defective heterotrimer assembly and, consequently, the manifestations of Alport syndrome.