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Cystine stones are always forming

Will you help CONTROL or IGNORE cystine buildup?With cystinuria, it’s only a matter of time before urinary cystine buildup leads to painful cystine stones. Hear how other people in the community have made the choice to actively manage their cystinuria.

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What is Cystinuria?

First, it’s something you’re born with

Unlike more common kidney stones, cystine stones occur in people born with cystinuria—a rare, lifelong, and serious genetic disorder. Because cystinuria is genetic, other family members may also have it.

Picture showing how a person with cystinuria inherited 2 abnormal genes—1 from each parent.

Cystinuria is an autosomal recessive disorder. “Autosomal recessive” refers to the way the disease is passed down through family members. People with cystinuria inherit 1 mutated (or abnormal) gene from each parent, as shown here.

Second, it’s chronic

Cystinuria results in the ongoing formation of a specific type of kidney stone called a “cystine kidney stone.” When cystinuria is not properly managed, you will continue to form stones. The consequences of repeat stones can affect many aspects of your life.

Picture of cystine stones

Cystine stones

Distinct from other types of kidney stones, cystine stones are often larger, harder, and more frequent. Due to the larger stone size, cystine stones may be more difficult to pass, often requiring surgical or urological procedures (procedures related to the urinary tract) to remove.

Other kidney stones

There are many different types of kidney stones. Other more common kidney stones are often smaller and can form in people without genetic disorders. The more common kidney stones may occur much less frequently than cystine stones; in some cases, they can be prevented altogether through lifestyle changes.

Whether or not you are experiencing symptoms related to a kidney stone event, cystine stones may be forming because of continuous buildup of cystine.

Mechanism of Disease

Reduce your risk of forming another cystine stone

Because cystinuria is a lifelong genetic disorder, if not properly managed, you will always be at risk of forming stones due to the continuous buildup of cystine in your urine.

People with cystinuria are born without the ability to remove cystine from their urine properly. This means they have too much cystine in their urine.

When urinary cystine levels are above the solubility limit (>250 mg/L), cystine stones begin to form.

Let’s take a closer look

Zoomed in picture of kidneys in a person who doesn’t have cystinuria showing  how cystine in the urine filters through the transporters of the kidney.

In the kidneys of healthy individuals, specific transporters filter out certain building blocks of protein (also called amino acids), such as cystine. These transporters help remove cystine from the urine, keeping urinary cystine levels balanced.

Picture of an Erlenmeyer flask containing the urine of a person who doesn’t have cystinuria showing a healthy cystine level

In healthy individuals, a urinary cystine level below 30 mg/L is considered normal and healthy.

Zoomed in picture of kidneys in a person who has cystinuria showing how cystine in the urine cannot filter through broken transporters in the kidneys, leading to cystine buildup.

In the kidneys of people with cystinuria, these transporters don’t function properly and the normal cystine balance is disrupted.

Picture of an Erlenmeyer flask containing the urine of a person who has cystinuria showing an elevated cystine level, leading to cystine stone formation

As a result, cystine builds up in the urine. When urinary cystine levels exceed the solubility limit, generally higher than 250 mg/L, cystine binds together to form stones. Even though cystine is building up over time, people with cystinuria may not feel any obvious pain until a stone event occurs.

Understanding your disease is an important step toward managing it. The right management plan may help prevent stones from forming.

Management

Reduce your risk of forming another cystine stone

Whether you have had 1 stone or 35 stones, the thought of having another can be excruciating. But beyond the unpredictable pain and stress involved, each stone may require surgery and put your kidneys at risk for long-term damage such as renal insufficiency and end-stage renal disease.

You can reduce your risk of cystine stone formation by working with your doctor to establish a treatment plan to actively manage your cystinuria.

Management options

Adhering to basic therapeutic lifestyle changes

Drinking 3 to 4 liters of water per day, staying on a low-animal-protein and low-sodium diet, and taking medications to adjust the pH of your urine can help reduce your risk of stone formation.

Kidney stones tend to form in highly acidic environments, which is why it’s important to maintain a urine pH of 6.5 to 7.0 and to increase your fluid intake.

Cystine-binding thiol drugs

Removing cystine from your urine can help prevent stone formation. Cystine-binding thiol drugs bind to and help remove excess cystine in the urine. These treatments should be used along with therapeutic lifestyle changes.

Monitoring frequency

A 24-hour urine test is the best way to regularly monitor your urinary cystine level and check if you’re at risk of forming stones.

It is essential for people with cystinuria to keep their urinary cystine levels below 250 mg/L. Be sure to work with your doctor to regularly check your cystine level.

Surgical or urological procedures may be necessary when cystinuria is not optimally managed. Work with your doctor to establish a treatment goal to help prevent the next stone. Tracking your urinary cystine level and keeping it below 250 mg/L are important measures for the proper management of cystinuria.

Tap into other cystinuria resources

Cystinuria Resource: Rare Together

Join the Cystinuria Resource: Rare Together community on Facebook. This group is dedicated to individuals and families affected by cystinuria. This page offers information on cystinuria, as well as tips and advice on how to manage it, with the goal of preventing the next cystine stone.

International Cystinuria Foundation

Focused on supporting the cystinuria community by providing educational and health-related resources to affected individuals worldwide.

Check Orphan

Offers users an interactive platform whereby visitors have access to the latest news and information about rare, orphan, and neglected diseases.

National Kidney Foundation

Dedicated to making change through the awareness, prevention, and treatment of kidney disease for healthcare professionals, patients, and their families.

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