Kidney stones: How one common recurring symptom could signal a rare disease

(BPT) – Throughout her life, Kim had no explanation for the recurrent, painful kidney stones she experienced. Growing up she and her doctors dismissed these stones and associated pain for other conditions like menstrual cramps and irritable bowel syndrome (IBS). It wasn’t until her sister Joy passed away from the same disease that Kim received answers in the form of an official diagnosis — Kim’s kidney stones were the result of a rare, inherited disease called primary hyperoxaluria type 1 (PH1).

Kidney stones are a hallmark symptom of PH1. However, many people who experience recurrent stones in adulthood or even one kidney stone as a child do not consider or investigate a root cause, which can lead to delayed diagnoses and further complications. After watching her sister’s progressive PH1 symptoms, Kim is determined to ensure her sister’s memory lives on by sharing PH1 education and her own disease journey. Here’s some information to know about PH1, including signs and symptoms, to better understand what to look for and when to potentially suspect this rare disease.

What is PH1?

PH1 causes an overproduction of oxalate — an unneeded waste product that cannot be broken down further — in the liver. Normally, oxalate is present only in small amounts, is not used by the body for anything and needs to be eliminated by the kidneys. The overproduction of oxalate can lead to the formation of painful and recurrent kidney stones as well as progressive damage — meaning it can get worse over time and cause permanent damage.

How rare is PH1?

As a rare disease, PH1 affects approximately 1 to 3 individuals per million in the United States and Europe, with an estimated 1,300 to 2,100 diagnosed cases across geographies. In some regions, such as the Middle East and North Africa, the genetic prevalence of PH1 is estimated to be higher.

After getting diagnosed with PH1, Kim took a genealogy test that showed she is, in part, of Middle Eastern descent, giving her a higher likelihood of having PH1. Knowing this helped fuel her vigorous research to learn about disease management options, especially since she and her siblings are more likely to have PH1 due to their ancestry.

What are the common symptoms of PH1?

Most people with PH1 have their first symptoms as children or teens, but some people don’t have signs until they’re adults. Kidney stones are the most common symptom of PH1, which may include pain in the side of the body, painful and/or bloody urination and urinary tract infections. However, not everyone with PH1 may have kidney stones. Other symptoms of PH1 include, but are not limited to, nephrocalcinosis (crystal deposits in kidney tissue), failure to thrive in babies and end-stage kidney disease (kidney failure).

Kim was not the first person in her family to experience kidney stones. In fact, this seemingly common symptom ran in her family. Her brother passed away at birth due to crystallization in his kidneys, and her sister also experienced kidney stones, among other PH1 symptoms, throughout her life. Their symptoms were undiagnosed by doctors for years until they received a formal diagnosis later in life — which unfortunately, was too late in her sister’s battle with PH1.

How are patients diagnosed with PH1, and how can they manage a positive diagnosis?

PH1 can be diagnosed by a doctor measuring oxalate levels in the urine or blood, and/or with a genetic test. While managing PH1 is life long, there are various ways to address the symptoms. A person diagnosed with PH1 should work with their doctor or care team to create a personalized care plan, which likely would include monitoring oxalate levels and kidney function. Management options include hyperhydration (drinking a lot of water to dilute urinary calcium oxalate), dialysis (removing oxalate and other waste products from the blood) and certain supplements or oxalate-lowering medications.

How often are people diagnosed with PH1?

For many patients, like Kim, PH1 is not diagnosed immediately. Half of people living with PH1 may be undiagnosed. Unfortunately, Kim’s sister was also diagnosed later in life and, due to the delayed diagnosis, developed severe oxalosis throughout her body, including in her legs and heart before passing away.

Today, Kim is passionate about telling her story, so she was happy to be sponsored to share her story with Alnylam. She also advocates for herself and others with PH1. To learn more about PH1 and access educational resources about the symptoms and management of PH1, visit www.TakeOnPH1.com. If you suspect you may have PH1, talk to your doctor about your symptoms and testing.

A message from Alnylam Pharmaceuticals

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