Dent disease symptoms, causes and treatment

What is Dent disease?

Dent disease, also known as Dent's disease, can cause protein in the urine (pee), too much calcium in the urine, kidney calcifications or buildup, kidney stones and chronic kidney disease (CKD). 

There are two kinds of Dent disease, type 1 and type 2, both caused by mutations in genes. Researchers believe that when these mutations are present, the tubules (tiny tubes that filter your blood) in the kidneys are damaged and they aren't able to reabsorb nutrients like they should, leading to kidney damage. 
 

What are the signs and symptoms of Dent disease?

Signs and symptoms of Dent disease vary from person to person, even within the same family. These may include:

• Smaller, low-molecular weight proteinuria (protein in your urine)
  • From the tubules in your kidneys, not always found in routine testing.
• Hypercalciuria (too much calcium in your urine)
• Nephrocalcinosis (calcium buildup in your kidneys)
• Kidney stones (Calcium oxalate stones or calcium phosphate stones)
• Blood in your urine (hematuria)
• Hypophosphatemia (low levels of phosphorus in your blood)
• CKD 

There are two subtypes of Dent disease. Dent disease type 2 can also include intellectual disabilities (conditions that affect learning and thinking skills), cataracts (clouding in the eye lens that makes vision blurry), and hypotonia (low muscle tone). 

What causes Dent disease?

Dent disease is caused by genetic mutations.

• Type 1 is caused by a mutation in the CLCN5 gene, and only the kidneys are involved.
• Type 2 is caused by a mutation in the OCRL1 gene, and other body systems such as the brain, eyes, and muscles can be involved. 

Both genes make proteins that are important for your kidney function. These proteins help the kidney tubules to reabsorb the water and nutrients your body needs. 

Researchers believe that these mutations can damage the tubules in your kidneys, and the reabsorption of important nutrients does not happen as it should. Over time, this leads to kidney damage.

It's estimated that 2 out of every 3 men with Dent disease will have CKD. 
Genetic testing can help find the cause of kidney disease, especially when it runs in families or starts at a young age. It can confirm a diagnosis, guide treatment decisions, and help predict how the disease may progress. Testing can also give family members important information about their own risk and help with future planning and care. 

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How is Dent disease diagnosed? 

If you show signs and symptoms of Dent disease, doctors will do the following to confirm a diagnosis:

• Take a detailed patient history
• Perform a thorough clinical exam (when a doctor checks your body for signs of illness by looking, listening, and feeling for anything unusual)
• Test urine for low molecular weight proteinuria and calcium levels in the urine

Genetic tests can also confirm if you have a mutation. It's important to note that a negative genetic test cannot rule out Dent disease, because there may be unknown genetic causes. 

A kidney biopsy isn't needed to diagnose Dent disease because genetic testing and lab findings are enough for a diagnosis, but you may have had one in the process.. If you have had a kidney biopsy, it might show non-specific damage that may be similar to damage that is seen from focal global glomerulosclerosis or focal segmental glomerulosclerosis, which are other types of rare kidney diseases.

How do doctors treat Dent disease?

Since there is no cure for Dent disease, treatment focuses on three goals while managing symptoms:

1. Reducing the level of calcium in your urine
2. Preventing kidney stones and reducing the amount of calcium in your urine nephrocalcinosis (too much calcium in your urine)
3. Preventing future damage to the kidneys 

For people who progress to kidney failure, you will need dialysis or a kidney transplant. So far, Dent disease has not been shown to come back after a kidney transplant. 

Treatment strategies to address these goals can include:

• Lower the amount of sodium (salt) you eat
• Thiazide diuretics (a specific kind of diuretic that works in the kidneys' tubules to remove extra salt and water)
• Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), medicines that help control blood pressure. These treatments can be used when doctors are also treating bone disease and delayed growth:
  • Vitamin D (used with caution because it can cause calcium in the urine to get worse)
  • Growth hormone therapy  

What can I expect while living with Dent disease?

Living with Dent disease looks different for everyone. Your symptoms and treatment plan may vary. When you have a rare chronic disease, it's important to take care of your overall health and wellbeing. This includes taking care of your physical and mental health, making healthy lifestyle choices like being active, eating healthy, and focusing on emotional health, which includes having a good support system, managing stress and seeking professional support when necessary. 

Living with Dent disease looks different for everyone because your symptoms and treatment plan can vary. When you have a rare chronic disease, it's important to take care of your physical and mental health to support your wellbeing. This includes making healthy lifestyle choices like being active and eating healthy. It also means taking care of your emotional health, which includes having a good support system, doing your best to manage your stress and seeking professional help when necessary. It's normal to feel sad, anxious, and overwhelmed. Mental health professionals, like therapists, counselors and others, can teach you strategies to cope with these feelings. Talk to your health care providers about resources they may know about. 

Genetic diseases can bring up complicated feelings and questions about the future. Genetic testing and counseling can be helpful to understand the risks for current and future children.