This site is intended for healthcare professionals
Diagnosis and management of primary hyperoxaluria type 1
Declaration of sponsorship Alnylam Pharmaceuticals

Adult with recurring kidney stones

Declaration of sponsorship Alnylam Pharmaceuticals
Read time: 10 mins
Last updated:6th Apr 2021
Published:6th Apr 2021

Adult presentation

A woman has returned with recurrent urolithiasis. An ultrasound reveals a stone of approximately 6 mm in diameter, which requires surgical intervention.

A10087 - Alnylam - Medthority 8-07.png

Hypothetical patient representative of typical presentations.

Knowledge check


Challenges in the surgical management of urolithiasis

Calcium oxalate is the most common component of kidney stones8. As such, in patients overproducing oxalate, recurrent urolithiasis is a common presentation of adults with PH11,3. While smaller stones may pass in a short space of time, those >5 mm in diameter can take several weeks to pass and 50% of these will require surgical intervention8.

In patients with PH1, kidney stones are usually 95% calcium oxalate, light in colour (cream to pale yellow-brown) and nonhomogeneous in appearance (Figure 1)1,9. Observing the nature of these stones, followed by urinary analysis, can aid diagnosis1. Refer to the European Association of Urology Guidelines on Urolithiasis ( for further guidance on the investigation and management of stones in the urinary tract.

A10087 - Alnylam - Medthority-17.png

Figure 1. Differences in calcium oxalate stones from different patient groups (reproduced from Hoppe 20129).

Stone removal procedures are traumatic for patients and families and a source of great concern for those with PH1, and they may lead to acute episodes of renal decline10. Recurrences can be frequent, unpredictable and may continue throughout a patient's life10.

Suspicion prompts referral

Identifying patients with PH1 early in their disease course is essential to ensure prompt management and reduce oxalate levels in order to preserve renal function3,4. The involvement of a specialist team is necessary to reach a diagnosis. As such, recognising the warning signs and making a prompt referral may help patients begin managing PH1 early (see PH1 diagnosis)4.

If you suspect, refer.

See the PH1 management section for management options in PH1.

Knowledge check

Management options


Developed by EPG Health for, with all content provided by Alnylam Pharmaceuticals. Learning Zone sponsored and funded by Alnylam Pharmaceuticals. Please note that this material is intended for healthcare professionals only. 

Date of preparation: March 2021 │ OXL-CEMEA-00010

© Copyright 2021