Primary hyperoxaluria (PH) is a rare genetic condition that affects how your body processes a natural substance called oxalate. This guide explains the disease, its causes, symptoms, treatments, and how to manage living with it.
What is Primary Hyperoxaluria?
Primary hyperoxaluria is a condition where your liver produces too much oxalate, a chemical that is normally eliminated from your body through urine. When oxalate levels are too high, it can combine with calcium to form hard crystals in your kidneys and other parts of your body. These crystals can lead to kidney stones, kidney damage, and other complications if not managed properly.
There are three main types of primary hyperoxaluria (PH1, PH2, and PH3), each caused by mutations in different genes involved in oxalate production. PH1 is the most common and severe form.
Key Facts About Primary Hyperoxaluria
Background
- The condition was first described in the 1920s and is now recognised as a rare but serious genetic disorder.
- It is often diagnosed when individuals experience recurrent kidney stones or kidney failure at a young age.
Causes
- PH is caused by mutations in specific genes (AGXT, GRHPR, or HOGA1) that affect how your liver processes oxalate.
- These mutations result in overproduction of oxalate, which cannot be properly eliminated by the kidneys.
Incidence and Prevalence
- Incidence: Around 1–3 new cases per million people are diagnosed each year globally.
- Prevalence: Approximately 1 in 58,000 people are affected by primary hyperoxaluria. However, the condition may be underdiagnosed due to its rarity and nonspecific symptoms.
Who is Affected?
- Age: Symptoms can appear at any age but often begin in childhood or adolescence. Severe forms may present in infancy.
- Gender: Both males and females are equally affected.
- Ethnicity: PH occurs worldwide and affects all ethnic groups equally.
Geographic Distribution
- There are no specific regions with higher prevalence; cases have been reported globally.
How Does Primary Hyperoxaluria Impact You?
Symptoms
The symptoms of PH depend on the severity of the condition and how much oxalate has built up in your body:
Kidney Symptoms:
Recurrent kidney stones (hard deposits that form in the kidneys).
- Blood in the urine (haematuria).
- Pain in the lower back or sides (renal colic).
- Frequent urinary tract infections (UTIs).
Systemic Symptoms (if untreated):
- Kidney failure due to long-term damage from oxalate crystals.
- Oxalosis (a condition where oxalate crystals deposit in other parts of the body, such as bones, eyes, skin, and heart).
Living With Primary Hyperoxaluria
Living with PH often involves managing symptoms, preventing complications like kidney stones or kidney failure, and adhering to lifelong treatment plans.
Expected Life Expectancy
With early diagnosis and effective treatment, many individuals with PH can live full lives. However, untreated severe cases may lead to life-threatening complications such as end-stage kidney disease.
Managing and Treating Primary Hyperoxaluria
Available Treatments
Treatment for PH focuses on reducing oxalate production and preventing complications:
- Medications:
- RNA Interference Therapies: Newer treatments like lumasiran target the liver’s production of oxalate by silencing specific genes involved in its production. These therapies have shown significant success in reducing oxalate levels.
- Vitamin B6 (pyridoxine): Effective for some individuals with PH1 as it helps reduce oxalate production.
- Hydration:
- Drinking large amounts of water helps dilute urine and reduce the risk of crystal formation.
- Dietary Changes:
- Avoid foods high in oxalate such as spinach, nuts, chocolate, and rhubarb.
- Limit salt intake to reduce calcium excretion into urine.
- Kidney Stone Management:
- Procedures like extracorporeal shock wave lithotripsy (breaking up stones using sound waves) or surgery may be needed for recurrent stones.
- Dialysis:
- In advanced cases with kidney failure, dialysis may be required to remove excess oxalate from the blood.
- Liver or Kidney Transplantation:
- For severe cases (e.g., end-stage kidney disease), a combined liver-kidney transplant may be necessary to address both organ damage and correct the underlying metabolic defect.
Ongoing Clinical Research
Research into primary hyperoxaluria continues to focus on improving diagnosis and treatment options:
- Gene Therapy: Scientists are exploring ways to correct the genetic mutations responsible for PH.
- New Medications: Trials are underway for additional RNA interference therapies targeting different pathways involved in oxalate production.
- Biomarker Studies: Researchers are identifying biomarkers (measurable indicators) to improve early diagnosis and monitor treatment effectiveness.
Support Groups and Resources
If you or a loved one has been diagnosed with primary hyperoxaluria, connecting with support groups can provide valuable information and emotional support:
- Oxalosis & Hyperoxaluria Foundation (OHF) (ohf.org) – Offers resources for patients with primary hyperoxaluria worldwide.
- Rare Disease UK (raredisease.org.uk) – Provides support for individuals living with rare conditions like PH.
- National Kidney Foundation UK (kidney.org.uk) – Offers resources for managing kidney-related conditions.
- Global Genes (globalgenes.org) – Connects patients with advocacy groups for rare diseases.
Remember:
This information is intended for general knowledge and educational purposes only and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
