Hyperuricosuria / hyperuricemia / HUU (SLC2A9-related) - Dog

What does this test examine?

This genetic test analyses the SLC2A9 c.563G>T variant in dogs. The trait is known as hyperuricosuria, hyperuricemia, HUU, urate urolithiasis risk, increased urinary uric acid and increased uric acid in blood and urine. SLC2A9 encodes a transport protein involved in uric acid handling in the liver and kidneys.

What does HUU mean?

Dogs with two copies of the tested variant excrete increased amounts of uric acid. This can lead to ammonium urate crystals and urate stones in the bladder, ureter or kidney. Not every homozygous dog develops stones, but the genetic result identifies a clear predisposition. Possible signs include frequent small urinations, straining, blood in urine, cloudy urine, abdominal pain, recurrent urinary problems or sudden inability to urinate due to obstruction.

Inheritance and result

HUU follows autosomal recessive inheritance. Carriers have one copy of the variant and are usually not clinically affected, but can pass the variant on. Dogs with two copies have the risk genotype for hyperuricosuria and hyperuricemia. The test is relevant in breeds where the variant is more frequent, while HUU can also occur outside those breeds.

Practical value of this test

The test is useful for breeders and owners because it makes a hidden recessive predisposition visible before problems or breeding combinations arise. For breeders, the result helps avoid carrier-to-carrier matings while still allowing responsible use of valuable carriers. For owners and veterinarians, it adds direction in dogs with urinary signs or in breeds with increased risk of urate stones.

Result in brief

• Clear: the tested SLC2A9 variant was not detected.
• Carrier: one copy is present and can be passed on.
• Risk genotype: two copies cause the tested predisposition to hyperuricosuria and hyperuricemia.