SLC34A1 and urolithiasis: Our reports provided clinical evidence of the effect of monoallelic heterozygous variants in SLC34A1. Increased urinary phosphate and calcium excretion, elevated plasma 1,25(OH)2D3 and urolithiasis were shown in heterozygous SLC34A1-deficient mice (SLC34A1+/-), indicating the dominant negative effect of the mutant SLC34A1 protein on the function of the wildtype [19].