Cystinuria type I-A / cystine stones (SLC3A1-related) - Cat

Type I-A cystinuria and cystine stones

This genetic test analyses the SLC3A1 variant c.1342C>T, which causes type I-A cystinuria in cats. Cystinuria is an inherited metabolic disorder in which cystine and related amino acids are not reabsorbed efficiently. Cystine can then accumulate in the urine and form crystals or stones in the bladder and urinary tract.

Cats with cystine stones may show painful or difficult urination, small volumes of urine, blood in the urine or urinary obstruction. Obstruction is especially important because rapid action may be needed.

Practical value of this test

• Determines whether the cat is clear, a carrier or genetically affected for the tested SLC3A1 variant.
• Helps breeders avoid risk combinations and manage carriers deliberately.
• Provides clear genetic information in cats with cystine crystals, cystine stones or recurrent urinary signs.

The trait follows an autosomal recessive mode of inheritance. Cats with two copies of the variant are genetically affected; carriers can pass the variant to offspring.