The clinical manifestations of PH1
Primary hyperoxaluria type 1 (PH1) has heterogeneous clinical manifestations.1 However, diagnosing PH1 can be straightforward if you know what to look for.2,3
Look closely, as disease presentation varies widely1,4
PH1 is a heterogeneous disease.1,5 At any age, patients may present with one or more of the clinical manifestations below.1,6
Kidney stone in a child1
Recurrent urolithiasis5
Family history of stones3
Nephrocalcinosis3,5,7
Progressive kidney function decline of unknown cause that commonly progresses to end-stage renal disease (ESRD)3,5,7
Failure to thrive in infancy1
Though kidney stones are the most common clinical manifestation, there may be PH1 patients who are not stone formers.1.7
PH1 is often overlooked6,8,9
Historically, PH1 has been underdiagnosed. This may be due to several factors, including a low index of suspicion and symptomatology that is nonspecific or shared with other diseases.6,8-10
Variable rates of disease progression among PH1 patients and delays in diagnosis contribute to the burden of the disease.6,11
Clinical manifestations may not be recognized.6 Additionally, they may not be considered as indicative of PH1, delaying diagnosis until end-stage renal disease (ESRD).4,8,12-14 At that point, patients have irreparable kidney damage. 4,8,12-14
PH1 by the numbers
Kidney stones may be a sign of something more serious16
Recurrent kidney stones in an adult or any kidney stone in a child or adolescent could be a sign of PH1.16,17
Refer these patients for a full work-up and confirm PH1 with genetic testing.16
Regardless of renal status, acute decline can occur suddenly18,19
Though the course of PH1 is well characterized, with patients typically advancing toward ESRD, the rate of progression is variable.1,6,11 In some instances, renal function can decline after a single incident of dehydration due to acute illness or intense physical activity.18-22 This can occur even in patients with previously stable disease.20
PH1 can be fatal, often due to complications of ESRD and/or systemic oxalosis1,6
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 toxicity from calcium oxalate crystal deposition.6,7
Diagnose as soon as possible; prompt management may mitigate damage.1-4,7,25
Watch the Skinner family discuss their daughter Claire’s diagnosis
When their daughter Claire was born, everything seemed normal. Claire’s diagnosis of PH1 came as a shock, and both the Skinners and their physicians were faced with the challenge of learning about and managing her rare disease.
"On the outside, everybody looks normal. They act normal…but everything with PH1 is really internal, and it's what's going on inside, which most people don't know, and most people don't recognize."
