Table 1.

Classification system for cystinuria according to Brons et al. 2013 [26].

Phenotype		Type I-A	Type II-A	Type II-B	Type III
Mode of inheritance		Autosomal recessive	Autosomal dominant	Autosomal dominant	Sex limited
Gene		SLC3A1	SLC3A1	SLC7A9	Undetermined
Sex		Males and females	Males and females	Males and females	Intact adult males
Androgen dependence		No	No	No	Yes
COLA μmol/g creatinine *	homozygous	≥8000	≥8000		≤4000
	heterozygous	≤500	≥3000	≥700
Breeds		Newfoundland Landseer Labrador	Australian Cattle Dog	Miniature Pincher	Mastiff and related breeds Scottish Deerhound Irish Terrier

* normal ≤ 500 μmol/g creatinine.