Affected Gene: SLC3A1
 Transmission: Autosomal recessive
 Mutation: CanFam3.1 10 g.46700948 delG
 OMIA Link: 001881-9615

Breeds Recommended for Testing: Labrador Retriever

Symptoms:
Cystinuria Type IA causes a defective reabsorption of cystine in the proximal renal tubule, leading to precipitation of cystine in the urine. This results in the formation of crystals and stones, leading to urolithiasis and urinary tract obstruction. Stones can lodge in the bladder, urethra, or kidneys, causing partial or complete urinary blockage, which may lead to kidney failure.

References:
Brons AK, Henthorn PS, Raj K, et al. (2013)
 SLC3A1 and SLC7A9 mutations in autosomal recessive or dominant canine cystinuria: a new classification system.
 J Vet Intern Med 27:1400-8. PubMed: 24001348
Henthorn PS, Liu J, Gidalevich T, Fang J, Casal ML, Patterson DF, Giger U.
 Canine cystinuria: polymorphism in the canine SLC3A1 gene and identification of a nonsense mutation in cystinuric Newfoundland dogs.
 Hum Genet. 2000 Oct;107(4):295-303.