Not all kidney disease has the same root cause; some may be caused by genetic conditions passed down from parents, or other kidney diseases may be caused by high blood pressure or diabetes.
In this article, we break down the causes of polycystic kidney disease and chronic kidney disease.
Key Points
- Polycystic kidney disease (PKD) is a genetic disease that causes cysts to grow inside the kidneys. Chronic kidney disease (CKD) is a progressive disease that damages the kidneys over a period of time.
- PKD causes large cysts to grow in the kidneys and damage the surrounding tissue, which can cause kidney disease.
- Like CKD, PKD requires early detection, treatment, and management to give the person the best chances of slowing disease progression and preventing kidney failure.
Polycystic Kidney Disease
Polycystic kidney disease (PKD) is a genetic condition that causes cysts (fluid-filled sacs) to grow in the kidneys. As the cysts become bigger, the kidneys become bigger along with them. The kidneys slowly begin to lose their ability to function correctly, which can eventually lead to kidney failure.
PKD is one of the most common genetic disorders, affecting roughly 500,000 people in the U.S. ARPKD is the rare form of PKD and affects 1 in 20,000 children.
There are two different types of PKD:
1. Autosomal dominant PKD (ADPKD).
ADPKD is one of the most common genetic kidney diseases and is the most common type of PKD. Approximately 9 in 10 people with PKD have ADPKD. This genetic kidney disease causes cysts to grow in the kidneys that can also spread to other organs, such as the liver.
2. Autosomal recessive PKD (ARPKD).
ARPKD is the less common type of PKD and causes cysts to grow in the kidneys and can also affect the liver.
Signs and symptoms of PKD
Symptoms of ADPKD generally begin in adults between the ages of 30 and 50 years old. Symptoms may include:
- Headaches
- Kidney stones
- High blood pressure
- Urinary tract infections (UTIs)
- Blood in the urine
Other health problems that ADPKD can cause:
- Heart problems
- Kidney failure or end-stage kidney disease (ESKD)
- Cysts in the liver or pancreas
- Kidney pain
- UTIs
- Kidney stones
- Preeclampsia (high blood pressure that occurs during pregnancy)
Symptoms of ARPKD may start before the baby is born, in childhood, or at birth. Symptoms of ARPKD before a baby is born may present via ultrasound imaging, showing that the kidneys are bigger than they should be. Or if there is not enough amniotic fluid around the baby in the womb.
Symptoms of ARPKD at birth may include:
- High blood pressure
- Vomiting formula or breast milk after feeding
- Breathing problems
- Swollen belly
- Issues with the development of the baby’s legs, arms, and face
Symptoms of ARPKD in childhood may include:
- High blood pressure
- Lower than average weight and height
- Varicose veins
- Pain in the side or back
- UTIs
What causes polycystic kidney disease?
A gene defect or mutation causes both types of PKD. In most cases, the defective gene passes from a parent to the child.
ADPKD is caused by a mutation (change) in a specific gene (commonly the PKD1 or PKD2 genes). “Autosomal dominant” means that only one parent needs to carry the gene mutation for ADPKD in order for the child to be born with it. If both parents have ADPKD, there is a 75% chance it will pass down to the child. If one parent has ADPKD, there is a 50% chance it will pass down to the child.
In a few PKD cases, the cause is spontaneous. This is where the gene mutation develops on its own without a parent having a copy of the defective gene.
ARPKD is caused by a mutation in the gene PKHD1 and is passed down from both parents to the child (autosomal recessive). For a child to be born with ARPKD, both parents need to be carriers of the mutated PKHD1 gene. A carrier has the mutated gene but does not have the disease. ARPKD typically does not affect every generation of a family.
When both parents are carriers of the PKHD1 gene, their child has a 25% chance of being born with ARPKD. There is a 50% chance of being a carrier of the PKHD1 gene or a 25% chance of being a carrier for the gene or not having the gene.
How is polycystic kidney disease diagnosed?
Specific tests, such as an ultrasound, CT scan, or MRI, can be used to detect the size and number of kidney cysts. Healthcare providers can use the tests to evaluate the health status of the kidney tissue.
ARPKD can be detected with genetic testing that looks for changes in the PKHD1 gene. Genetic testing can be done using a sample of saliva or blood.
Treatment and management
The severity of PKD will vary from person to person, even in families. Some people with PKD will progress to kidney failure, while others might only ever have a mild disease with no progression to kidney failure.
There is no known cure for ADPKD, with strategies being used to help manage symptoms and health conditions that are associated with this disease. Recently, the FDA approved the first treatment for ADPKD, which has been shown to slow down the progression from ADPKD to kidney failure.
While there is also no cure for ARPKD, there are strategies that can help manage health problems and symptoms as they arise. Management strategies for ARPKD include:
- Antibiotics
- Peritoneal dialysis, or hemodialysis for some children
- Medicine to lower blood pressure
- Growth hormones
- Liver transplant
- Kidney transplant
You can also ask a healthcare provider if there are any clinical trials for ARPKD or ADPKD that your child or yourself can participate in.
Chronic Kidney Disease
Chronic kidney disease (CKD) is a condition that is characterized by progressive damage to the kidneys. When the kidneys are damaged, they lose their ability to filter out waste products and excess fluids from the bloodstream. This can cause a build-up of waste and fluid, resulting in additional health problems such as heart disease, stroke, or high blood pressure.
If left unmanaged or untreated, the damage to the kidneys becomes worse and may cause the kidneys to stop working entirely (kidney failure).
In the United States, CKD affects more than 1 in 7 or 37 million people.
What causes chronic kidney disease?
The most common causes of CKD are hypertension (high blood pressure) and diabetes. Other kidney problems that can lead to the development of CKD:
- Kidney cancer
- Glomerulonephritis
- Lupus nephritis
- Inherited diseases or polycystic kidney disease (PKD)
Signs and symptoms of CKD
Most people with early-stage CKD may not experience any symptoms. Over time, as the kidneys fail to effectively remove waste products and excess fluids, symptoms of CKD start to present. During the later stages of CKD, the following symptoms may be noticed:
- Swelling (edema) of the feet, ankles, and legs
- Feeling tired and week
- Itchy skin
- Pain in the lower back
- Urinating more frequently or less than normal
- Insomnia or trouble falling asleep
- Nausea or vomiting
- Less of an appetite
Other health problems that CKD can cause include anemia, heart disease, high blood pressure, edema, and high phosphorus and potassium levels. The only way to tell how well the kidneys are working (especially if there are no signs or symptoms) is to get tested for kidney disease.
How is chronic kidney disease diagnosed?
The most effective way to help prevent CKD progression is by early detection. Healthcare providers will perform urine or blood tests to confirm the disease and its stage (disease progression). The most frequently ordered tests are glomerular filtration rate (GFR), a blood test for creatinine, and an albumin to creatinine ratio urine test.
Additional tests, such as a CT scan of the kidneys or urinary tract or a biopsy of the kidney, can be used to determine the extent of damage to the kidneys and if there are other issues, such as a kidney stone or tumor.
Treatment and management
Early diagnosis and treatment of underlying causes of CKD are crucial in CKD patients.
Treatment and management of CKD are focused on:
- Delaying or stopping disease progression
- Diagnosing and treating the underlying cause of CKD and its associated complications
- Planning for renal replacement therapy
CKD may often be managed by making lifestyle changes to help reduce or prevent further damage to the kidneys.
Panoramic Health
Panoramic Health is a physician-led, value-based kidney care platform that understands how to best approach kidney disease and create positive results for patients. Our priority is healthy patients. Through our integrated value-based care platform, we are able to deliver better patient outcomes at a lower cost for everyone involved.
