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Familial Nephropathy (Cocker Spaniel Type)

Familial Nephropathy (FN) (Cocker Spaniel Type) is an inherited kidney disorder that leads to progressive kidney failure in Cocker Spaniels.

Affected Genes: COL4A4

Inheritance: Autosomal Recessive

Variant(canFam6):
chr25:40571574: T>A

Breed: Australian Cobberdog
Australian Labradoodle
Cockapoo*
Cocker Spaniel
English Cocker Spaniel
Welsh Springer Spaniel

General Information: Familial Nephropathy (FN) (Cocker Spaniel Type) is a genetic disorder affecting the kidneys of Cocker Spaniels, typically manifesting between 6 months and 2 years of age. In healthy dogs, protein should not be present in the urine; however, in dogs with FN, a defect in kidney function allows protein to leak from the blood into the urine, a condition that can be detected as early as five months of age. This leakage indicates kidney damage and leads to symptoms of chronic kidney disease, such as excessive thirst and urination, vomiting, loss of appetite, weight loss, weakness, and fatigue. Some dogs may also exhibit inappropriate urination due to increased water intake. Sadly, affected dogs often succumb to chronic kidney failure within a year of symptom onset, making early diagnosis and management critical for improving their quality of life.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for Familial Nephropathy (Cocker Spaniel Type) focuses on identifying mutations in the COL4A4 gene. This disorder is inherited in an autosomal recessive pattern, meaning a dog must inherit two copies of the mutated gene (one from each parent) to develop the disease. Carrier dogs, which possess one copy of the mutation, do not exhibit symptoms but can pass the gene to their offspring. When two carriers are bred, there is a 25% chance of producing puppies with the disease and a 50% chance of producing carriers. Genetic testing is essential for identifying carriers and making informed breeding decisions. To prevent the transmission of FN and avoid producing affected puppies, it is recommended to avoid breeding two carriers. Ensuring that at least one parent is free from the mutation helps reduce the risk of this severe kidney disorder and promotes healthier breeding lines.

References:
Davidson AG, Bell RJ, Lees GE, Kashtan CE, Davidson GS, Murphy KE. Genetic cause of autosomal recessive hereditary nephropathy in the English Cocker Spaniel. J Vet Intern Med. 2007 21(3):394-401.

Donner J, Kaukonen M, Anderson H, Moller F, Kyostila K, Sankari S, Hytonen M, Giger U, Lohi H. Genetic Panel Screening of Nearly 100 Mutations Reveals New Insights into the Breed Distribution of Risk Variants for Canine Hereditary Disorders. PLoS One 2016 11(8):e0161005.

Lees GE, Helman RG, Kashtan CE, Michael AF, Homco LD, Millichamp NJ, Ninomiya Y, Sado Y, Naito I, Kim Y. A model of autosomal recessive Alport syndrome in English cocker spaniel dogs. Kidney Int. 1998 54(3):706-719.