Primary hyperoxaluria type 1 (PH1) has heterogeneous clinical manifestations.1 However, if you know what to look for, working towards a diagnosis can be straightforward.2,3
PH1 is a heterogeneous disease.1,4 PH1 patients with identical genotypes, and even members of the same family, can have variable disease symptoms.4
Global genetic prevalence estimates of PH1 are greater than previously reported, particularly in geographic regions with high rates of consanguinity, indicating that a significant number of individuals at risk for PH1 may remain undiagnosed.5
Infant and child patients may present with one or more of the clinical manifestations below:1,6,7
Haematuria
Urinary tract infection
Stone passage
Chronic kidney disease
Failure to thrive in infants
Dysuria
End-stage kidney disease (ESKD)
Abdominal pain
Nephrocalcinosis
Family history of stones/kidney disease
Recurrent kidney stones
Chronic kidney disease
ESKD without history of stones
History of unrecognised symptoms
Nephrocalcinosis
Family history of stones/kidney disease
Kidney stones are the most common clinical manifestation and the one that most often leads to a diagnosis of PH1, though not all patients with PH1 may be stone formers.8–10 All patients suspected to have PH1 should undergo genetic assessment according to the ERKNet and OxalEurope 2023 clinical practice recommendations.11 Genetic testing can alter decisions on combined liver-kidney transplant and kidney-alone transplant.12
Though the course of PH1 is well characterised, with patients typically advancing toward ESKD, the rate of progression is variable.1,8,15 In some instances, kidney function can decline after a single incident of dehydration due to acute illness or intense physical activity.13,14,16–18 This can occur even in patients with previously stable disease.16
Once the estimated glomerular filtration rate declines to below 30–45 mL/min/1.73 m2, systemic oxalosis can occur because the kidney is unable to excrete oxalate effectively due to excess accumulation of calcium oxalate crystals.8,19
Diagnose as soon as possible to ensure prompt management.1–3,19,22,23
ERKNet and OxalEurope 2023 clinical practice recommendations advise that all patients with suspected PH1 undergo genetic testing11
“Zoe and Ryan (brother) were genetically tested following Nathan’s (brother) [PH1] diagnosis. At that time Zoe had no symptoms at all. We had no suspicion that there was anything wrong. The bloods were, it seemed OK, but her kidneys had a lot of kidney stones. How she was coping with that, I’ve got no idea.”
Becky
Recurrent kidney stones in an adult or any kidney stone in a child or adolescent could be a sign of a metabolic stone disease like PH1.7,24
Consider these patients for a full work-up and using genetic testing to help confirm PH1.7
See how genetic testing plays an important role in a PH1 diagnosis.1,3
PH1-INTR-00030 | January 2026
