Breeds Affected: Australian Cattle Dog
Samples Accepted: Blood, Buccal Swabs
Disease Information: The kidneys of dogs with Cystinuria Type II-A are unable to reabsorb certain amino acids. Excess cystine is excreted in the urine, resulting in urolithiasis, the formation of calculi (crystals, stones) in the urinary tract. This leads to obstruction of the urinary tract and recurrent cystitis.
Inheritance Information: Cystinuria Type II-A is autosomal dominant, meaning that animals with just one copy of this allele will be affected. 50% of their offspring will also be affected.
The possible genotypes are:
n/n The dog is normal, and cannot produce affected offspring.
n/CYS2A The dog is affected, and 50% of the offspring will be affected.
CYS2A/CYS2A The dog is affected, and 100% of the offspring will also be affected.
– Affected animals (n/CYS2A, CYS2A/CYS2A) should not be used for breeding.
Test Information: This mutation test identifies a 6 base deletion in exon 6 of the SLC3A1 gene.
Brons, A.K., Henthorn, P.S., Raj, K., Fitzgerald, C.A., Liu, J., Sewell, A.C., Giger, U.: SLC3A1 and SLC7A9 mutations in autosomal recessive or dominant canine cystinuria: a new classification system. J Vet Intern Med 27:1400-8, 2013. Pubmed reference: 24001348. DOI: 10.1111/jvim.12176.
Further information is available at the Online Mendelian Inheritance in Animals website.