2026-07-03 | Primary hyperoxaluria type 1-current practice in the siRNA era: an ERA Genes & Kidney Working Group survey.

Primary hyperoxaluria type 1 (PH1) is a rare inherited metabolic disorder leading to the formation of kidney stones, nephrocalcinosis, and kidney failure. Besides, PH1 poses the risk of developing systemic oxalosis, a life-threatening condition with oxalate deposits in multiple organ systems. The rarity of the disorder combined with recent major additions to therapeutic options based on small interfering RNA (siRNA) therapeutics make a formal assessment of current practice and implementation of treatment recommendations an important asset. An international questionnaire survey was conducted among medical doctors involved in the treatment of patients with chronic kidney disease. The survey included 32 questions addressing demographics, diagnostics and therapeutics, and educational needs related to the care for PH1 patients. 176 participants from 43 countries completed the survey, the majority of them were from Europe. The results indicate clear shortcomings in the availability of recommended diagnostics, especially with regards to plasma oxalate. Genetic testing strategies often do not include patients who may have PH1, e.g. when the underlying cause of kidney failure is unknown or in patients with nephrolithiasis or nephrocalcinosis. Treatment modalities are only partly harmonized and intensified dialysis is not fully implemented across centers. Strategies toward combination of conventional therapeutics such as hyperhydration and pyridoxine with new siRNA therapeutics depend on the treating physician's expertise. The survey identifies clear needs regarding implementation of current treatment recommendations as well as important educational gaps. The advent of targeted treatment opportunities for PH1 comes with an increased need to provide guidance to the field. Filling the existing gaps will ensure that a growing number of patients get access to optimal care and novel life-changing therapies.

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2026-06-01 | P102 From stone disease to survival: sequential liver and kidney transplantation for type i primary hyperoxaluria in a resource-limited setting

Introduction

Type I primary hyperoxaluria is a rare autosomal recessive metabolic disorder caused by hepatic alanine-glyoxylate aminotransferase deficiency, leading to excessive oxalate production resulting in nephrolithiasis, nephrocalcinosis, end-stage renal disease, and systemic oxalosis. Definitive treatment is sequential or combined liver–kidney transplantation, where liver replacement corrects the metabolic defect and kidney transplantation restores renal function. We aimed to evaluate clinical characteristics and transplant outcomes of patients undergoing sequential liver with or without kidney transplantation in a resource-limited setting where diagnostic delay is common.

Methods

We retrospectively analyzed patients with primary hyperoxaluria who underwent liver transplantation with or without kidney transplantation at a tertiary care transplant center. The variables in our study are demographics, age at renal stone onset, diagnostic delay, age at time of liver transplant, prior urological interventions, duration of hemodialysis pre-liver transplant, graft-recipient weight ratio (GRWR), cold ischemia time, liver graft type, biliary ductal anatomy (single duct vs ductoplasty), cardiac involvement, one-year survival, liver-to-kidney transplant interval, and causes of mortality. Continuous variables are reported as mean ± standard deviation and categorical variables as frequencies and percentages.

Results

Fourteen patients were included, with a mean age at transplantation of 24.1 ± 11.4 years; 12 (85.7%) were male. Mean age at first renal stone was 10.79±8.78 years, while mean age at diagnosis was 23.29±11.17 years, resulting in a mean diagnostic delay of 11.89±13.40 years. Prior urological interventions were present in 11(78.6%). Mean duration of hemodialysis prior to liver transplantation was 17.07±9.07 months. Living donor liver transplantation was performed in all patients; mean GRWR was 1.26±0.72 and mean cold ischemia time was 35.71±18.80 minutes. Most grafts had single bile duct anatomy, with ductoplasty required in a minority. Cardiac involvement was common and predominantly manifested by diastolic dysfunction and pulmonary hypertension, with less frequent non-ischemic cardiomyopathy and largely preserved systolic function. One-year survival after liver transplantation was 10(71.4%). Mortality occurred early and was primarily attributable to sepsis, cardiac complications, and multiorgan failure

Conclusion

When contrasted with European registry cohorts that register earlier diagnosis and >85% one-year survival, patients in low-middle income settings present later with prolonged dialysis exposure and cardiac involvement yet can achieve acceptable short-term outcomes. Early metabolic screening, reduced diagnostic delay, and rigorous cardiac stratification may help to improve outcomes.

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2026-05-13 | Primary Hyperoxaluria type 3, first case reported in Uruguay

Primary hyperoxaluria (PH) comprises a heterogeneous group of autosomal recessive disorders of glyoxylate metabolism.Three genotypic forms (PH1-PH3) are recognized, and diagnosis can be challenging because of marked phenotypic heterogeneity.PH3, the least common form, is caused by pathogenic variants in the HOGA1 gene and generally follows a milder clinical course than PH1 and PH2.We report the case of a young woman with mild hyperoxaluria and preserved renal function with a genetic diagnosis of PH3.Genetic testing identified two pathogenic HOGA1 variants: c.208C>T, p.(Arg70Ter) and c.700+5G>T.This case highlights the broad clinical spectrum of PH3 and underscores the importance of genetic testing in establishing the diagnosis.

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