What Are Rare Kidney Diseases?

Rare kidney conditions, also known as chronic kidney diseases, occur when long-term damage to the kidneys causes them to stop working correctly. The kidneys filter and clean the blood by removing toxins through urine and excretion. When your kidneys don’t work properly, waste builds up in the body, resulting in health complications. 

Most rare kidney illnesses are hereditary, while some have complex causes. Inherited kidney illnesses are difficult to diagnose, manage, and treat, especially when they cause other issues. Often, kidney issues start with small cysts and infections that worsen over time.

Almost every child with rare kidney disease receives renal replacement therapy. At least 10%¹ of adults have inherited kidney disease, and it’s the fifth most common cause of end-stage renal disease after conditions like glomerulonephritis, pyelonephritis, and diabetes. Patients sometimes spend years consulting with several medical professionals before getting a definitive diagnosis. 

In the United States, kidney disease is rare when it affects fewer than 200,000 Americans. In Europe, a condition is rare when it affects fewer than 2,000 people. 

Is kidney failure a rare disease?

Kidney failure is not a disease—it’s the final stage of chronic kidney disease. Your doctor will diagnose kidney failure when your kidneys are down to 10–15% function. At this point, you need a kidney transplant or dialysis to keep you alive. 

Types of rare kidney diseases

There are around 150 different rare kidney disorders. These diseases have a high prevalence worldwide, with approximately 60–80 cases per 100,000 people in America and Europe. 

Abnormal hemolytic-uremic syndrome (aHUS)

Abnormal hemolytic-uremic syndrome (aHUS) is one of the most unusual kidney diseases. This condition can occur at any stage of life, and it causes blood clots in the tiny blood veins of the kidney. These clots may cause serious clinical problems if they restrict blood flow. The three main characteristics of aHUS are low platelet count, red blood cell death, and kidney failure.

Polycystic kidney disease (PKD) 

Polycystic kidney disease often runs in families, causing cysts on the kidneys and other internal organs. Over time, these cysts affect kidney functionality, which can eventually lead to kidney failure. Although treatments slow the growth of these cysts, PKD has no specific cure. 

Fabry disease

Fabry disease is a rare, inheritable kidney condition. It affects every organ in your body, including the kidneys, heart, and brain, and it may cause them to receive less blood than they need. Kidney failure or chronic renal disorders may eventually occur.

Glomerulonephritis

Glomeruli are blood vessels in your kidneys that support the filtering system. Glomerulonephritis damages the glomeruli, making them unable to do their job. Kidney failure may eventually occur. The underlying medical issue affects how your doctor diagnoses and treats this condition.

IgA nephropathy

IgA is an antibody your immune system produces. In IgA nephropathy, these antibodies build up and harm your kidneys' glomeruli. This condition often goes undiagnosed, and it might take a while to reverse the damage. IgA nephropathy can eventually result in kidney death, renal failure, or ongoing kidney injury. Although there is no known treatment for IgA nephropathy, medicines can delay damage.

C3 glomerulopathy

Another extremely rare type of kidney illness is C3 glomerulopathy (C3G). C3 is an immune system protein, and much like IgA nephropathy, the build-up of this protein in the kidneys causes damage to the glomeruli. The main causes or triggers of C3G are infection, genetic factors, and abnormal protein build-up in the blood. 

Cystinosis

This rare, inheritable condition causes your body to accumulate cystine crystals, an amino acid. It mainly affects the kidneys and eyes but can affect all areas of the body. The renal type most often occurs in infancy.

Treatments for this condition include cystine-reducing therapies and kidney transplants. Without timely treatment, cystinosis might cause kidney failure.

How do you know you have rare kidney disease?

Many of these diseases are silent, and diagnosing rare kidney diseases can be challenging. Not only can symptoms indicate other conditions, but signs also don't show up until the disease has progressed, causing kidney damage. 

You could have rare kidney disease if you have high blood pressure or diabetes. Your doctor can check your kidneys at least once a year with a screening blood test. The test can check your creatinine levels and estimated glomerular filtration rate (GFR) to see how well your kidneys work. 

Some of these signs may indicate rare kidney disease:

• Swelling of feet and hands: If your kidneys aren't eliminating enough excess sodium and water from your body, your feet or other lower areas may swell.

• Overall body weakness: Toxins can accumulate in the blood due to impaired kidney function, exhausting your energy and making you feel worn out.

• Shortness of breath: If your kidneys aren't eliminating enough water from your body, it may build up in your lungs and cause you to feel out of breath. 

• Aching in the spine and the back: Kidney problems might cause chronic back pain as they are located on either side of your spine in your lower back.

When do you consult a kidney expert?

If you experience these symptoms, you should see a nephrologist or primary care physician. A nephrologist is a kidney expert who can diagnose you, create an individual treatment plan, and discuss kidney disease care with you. 

The lowdown

Having a rare kidney disease can be challenging. Although there isn't a specific cure for most, you can now live longer and healthier with rare kidney diseases. Technological advancements and new medical interventions are accelerating our understanding of rare kidney diseases.

To protect your kidneys, strive for a healthier lifestyle and have frequent checkups.