Primary Hyperoxaluria Mutation Genotyping/Phenotyping

Inclusion Criteria: * Ages birth to 99 years in whom clinical information is available from medical records * Patients with a diagnosis of PH confirmed on previous genetic testing * Patients with clinical suspicion of primary hyperoxaluria (elevated urine oxalate of greater than 0.8 mmol/1.73 m2/day (\>70 mg/1.73 m2/day), history of kidney stones, and/or nephrocalcinosis documented by medical history or imaging studies * First or second degree family members of a patient with primary hyperoxaluria Exclusion Criteria: * Stone formers who do not have confirmed PH and do not meet the inclusion criteria for clinical suspicion of primary hyperoxaluria * Unwilling or unable to provide consent/assent.