Familial nephropathy (FN) – Cocker Spaniel type
Familial nephropathy or hereditary nephropathy is a group of genetic disorders of basement membrane (type IV) collagen that cause progressive glomerular disease. Familial Nephropathy (FN) has been referred to in several ways: kidney failure, fatal renal disease, juvenile nephropathy, renal cortical hypoplasia, hereditary nephritis (HN), Autosomal Hereditary Recessive Nephropathy (AHRN) in canines and Alport’s Syndrome in humans.
Affected dogs have proteinuria and juvenile-onset chronic renal failure. Familial nephropathy leads to progressive and irreversible renal failure between 6 months to 2 years. The first clinical signs are excessive water consumption, excessive urine volume, a slowdown in growth, weight loss, reduced appetite, vomiting and diarrhoea. Kidney dysfunction moving inexorably towards a premature death of the animal. Glomerular basement membrane (GBM) thickening and multilamellation is typical for familial nephropathy, and severity of GBM ultrastructural abnormalities varies with the clinical stage of disease. Expression of α3(IV) and α4(IV) chains is totally absent in the kidney of affected dogs. Features of obligate carriers are similar to those of unaffected dogs. Around 11% of English Cocker Spaniels are carriers of the genetic mutation responsible for the disease.
Lees, G.E., Helman, R.G., Kashtan, C.E., Michael, A.F., Homco, L.D., Millichamp, N.J., Ninomiya, Y., Sado, Y., Naito, I., and Kim, Y. (1998). A model of autosomal recessive Alport syndrome in English cocker spaniel dogs. Kidney Int 54, 706–719.