Heterozygous Individuals for AGXT and Kidney Stones

This study seeks to examine the effects of a heterozygous mutation of the AGXT gene in a stone forming population on endogenous oxalate production. Participants will consume a controlled low-oxalate diet and provide blood and urine samples to measure the amount of oxalate in their bodies. Subjects will then be administered an intravenous (IV) load of glycolate, providing additional blood and urine samples afterwards to measure any increase in oxalate levels.