Cystinuria type II-B / cystine stones (SLC7A9 c.964G>A) - Miniature Pinscher

What does this test analyse?

This genetic test analyses the SLC7A9 variant c.964G>A for cystinuria in Miniature Pinscher dogs. Cystinuria is also described as cystine urolithiasis, cystine stones, cystine calculi, bladder stones or kidney stones. The test determines whether the dog is clear, heterozygous positive/carrier or homozygous positive/affected for this specific variant.

What does cystinuria mean for the dog?

Cystinuria is an inherited metabolic disorder in which the kidneys fail to reabsorb cystine and related amino acids efficiently. As a result, too much cystine remains in the urine. Cystine is poorly soluble and can form crystals or stones in the bladder, urethra or kidneys.

The condition is also known as cystine urolithiasis, cystine stones, cystine calculi, bladder stones or kidney stones. Signs may include straining to urinate, frequent small urinations, blood in the urine, recurrent bladder inflammation and urinary obstruction. In male dogs, obstruction can become serious quickly because of the narrower urethra.

Practical value of this test

• Shows whether the dog carries the dominant cystinuria variant before breeding decisions are made.
• Helps breeders keep positive dogs out of risk combinations and strongly reduce the chance of affected offspring.
• Gives owners extra guidance for urinary signs, cystine stones or breed-specific screening, because one copy can already be clinically important.
• Supports planning, sales information and follow-up in lines where type II cystinuria is known.

Inheritance and result

The trait is inherited as autosomal dominant. In this form, one copy of the tested variant is enough to make the dog genetically positive for type II cystinuria. A dog with two copies passes the variant to all offspring.

Other causes can also produce urinary signs. This test therefore gives targeted genetic information about the variant for which the analysis was designed.