Familial nephropathy / ARHN / HN (COL4A4-related) - English Cocker Spaniel

What does this test examine?

This genetic test analyses the COL4A4 variant c.115A>T for familial nephropathy / ARHN in the English Cocker Spaniel. The condition is also known as familial nephropathy, FN, hereditary nephropathy, HN, autosomal recessive hereditary nephropathy, ARHN, Alport syndrome and type IV collagen-related kidney disease.

What does this disease mean?

Familial nephropathy is an inherited kidney disease in which the filtering structures of the kidney, the glomeruli, gradually become damaged. Affected dogs can develop urinary protein loss, reduced growth, increased drinking and urination, weight loss and eventually kidney failure.

COL4A4 encodes a component of type IV collagen, an important building block of the glomerular basement membrane. A loss-of-function variant disrupts this structure and explains why the kidneys are progressively affected.

Inheritance and result

The condition follows an autosomal recessive inheritance pattern. Dogs with two copies of the tested variant develop the tested form of familial nephropathy. Carriers have one copy, are usually not affected themselves and can pass the variant on.

• Clear: the tested variant was not detected.
• Carrier: one copy was detected; this is especially relevant for breeding plans.
• Affected: two copies were detected; this genotype causes the tested hereditary kidney disease.

Practical value of this test

The test makes hidden carrier status visible before breeding decisions are made. This matters because carriers can look healthy, while two carriers can produce affected puppies.

• Supports breeding selection and safe mating plans.
• Helps identify and manage risk lines.
• Provides clear genetic information when kidney disease or family history is relevant.
• For English Cocker Spaniels, this helps keep a known breed variant under control in breeding lines.