Primary hyperoxaluria type I

Primary hyperoxaluria type I is a rare autosomal recessive metabolic disorder caused by pathogenic variants in the *AGXT* gene, leading to a deficiency of the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase.

This enzymatic defect causes an overproduction of endogenous oxalate, which is primarily excreted by the kidneys as insoluble calcium oxalate.

The condition primarily impacts the renal system across pediatric and adult populations, characteristically manifesting as recurrent nephrolithiasis and progressive nephrocalcinosis.

As renal filtration declines, progressive hyperoxalemia can precipitate systemic oxalosis, resulting in extrarenal calcium oxalate deposition throughout the skeleton, myocardium, eyes, and vasculature.