Renal Tubular Acidosis
What is Renal Tubular Acidosis?
Renal tubular acidosis (often shortened to RTA) can be a complex disease with many outcomes. In the simplest of terms, renal tubular acidosis occurs when the blood in a person’s body becomes too acidic after their kidneys have stopped removing naturally occurring acids from the body through urination.
People who suffer from renal tubular acidosis may develop a handful of different ailments that negatively impact the kidneys — including chronic kidney disease, kidney stones, or even kidney failure. In addition, the buildup of acids in someone’s body can also lead to bone disease or slowed growth in children.
Renal tubular acidosis is a serious condition that has treatment options. If you believe you, a child, family member, or friend has renal tubular acidosis, it is important to seek medical attention immediately to reduce the severity of the condition and prevent kidney damage.
Knowing the basics of RTA, you may be wondering just how the condition progresses. It all begins with the digestion process, where the body creates acids to break down food.
These acids do their job to help with turning food into the energy you need to do basic things, and are then passed through the kidneys to either be removed from the body (through urination) or neutralized so that they are no longer acidic. Healthy, functioning kidneys prevent acid build up, which can throw off the body’s blood electrolyte imbalance and cause other problems.
While it may be strange to think of acids building up in your body, you should know that it’s a normal part of digestion; what isn’t normal is when the kidneys slow down or stop with removing extra acids from the body.
Healthy, fully functioning kidneys prevent acid build up, which can throw off the body’s blood electrolyte imbalance and cause the blood to become too acidic. Whenever kidneys fail to do this job, doctors
Whether you or a loved one has been diagnosed with renal tubular acidosis, or you believe that it may be a disease that you are at risk for, keep reading for more facts about the condition and what you should know, such as the different kinds of renal tubular acidosis, how the condition is treated, and what the prognosis is for most people who are diagnosed with the illness.
Although doctors may refer to a patient’s condition generally as renal tubular acidosis, you should know that there are actually multiple variants of the disease. In fact, medical researchers understand that there are three main types of RTA, and many of the differences depend on where in the kidney the disease dwells:
- Type 1 — Classical distal renal tubular acidosis: This form of the disease happens away from the beginning of the renal tubule — a portion of the kidney where the work of removing acid from the blood occurs. Distal renal tubular acidosis can lower blood potassium levels and create a variety of health problems, including weakness, paralysis, and heart arrythmias. It is possible for patients who suffer from Type 1 renal tubular acidosis to die if they fail to seek medical attention after an extended period of time. Researchers believe that Type 1 is either caused by a variety of health conditions such as lupus, sickle cell disease, or rejection of a transplanted kidney, though it can also be genetically inherited.
- Type 2 — Proximal renal tubular acidosis: This type of acidosis differs from Type 1 because it occurs near the start of the renal tubule (the region of the kidney that works to remove acid from blood). According to Riley Children’s Health at the Indiana University Health hospital, Type 2 renal tubular acidosis can happen as a symptom of other genetically inherited health conditions that impact how the body digests and uses food and nutrients.
- Type 4 — Hyperkalemic renal tubular acidosis: The third type of acidosis happens when the kidney doesn’t get rid of electrolytes in the blood. Normally, excess electrolytes are removed from the body through urination, but Type 4 renal tubular acidosis can prohibit this. In many cases, Type 4 is a side effect of some kinds of medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and blood pressure drugs. In other situations, Type 4 can be caused by health conditions such as lupus, Addison’s disease, or HIV.
You may have noticed that there is no Type 3 renal tubular acidosis. That’s because medical researchers now know that the formerly used Type 3 diagnosis is now likely a blending of Type 1 and 2, instead of being a separate form of the condition.
What does life expectancy look like for someone who has been diagnosed with renal tubular acidosis? In most cases, the prognosis is good, and many people recover with the help of medications that help to neutralize the building of acid in their blood.
While a RTA diagnosis can be scary, you should know that modern medical treatments have made it easier to recover from than ever before; in fact, seeking medical attention if you believe you have this disease can help reverse the negative effects the condition has on your body.
How is Renal Tubular Acidosis Inherited?
Researchers of renal tubular acidosis understand that genetics do play a role in the development of the disease.
For at least Types 1 and 2, the medical community believes that variations of the SLC4A1 gene can lead to a renal tubular acidosis diagnosis. According to the National Institutes of Health, passing the condition from parent to child requires only one parent to have a SLC4A1 gene mutation.
According to the European Renal Association — European Dialysis and Transplant Association (ERA-DETA), further research in the genetics of RTA have found six total genes that may be related to development of the disease, though most research shared with the public refers exclusively to the SLC4A1 gene.
Still, many people who are diagnosed with renal tubular acidosis have no family history of the condition. According to the National Institutes of Health, mutations in the SLC4A1 gene during a person’s lifetime can lead to the development of renal tubular acidosis, even if that person isn’t related to anyone else who has ever been diagnosed with the disease.
What Causes Renal Tubular Acidosis?
There are a variety of reasons why renal tubular acidosis develops, and some are specific to the different types of the disease.
Causes of Type 1 Distal Renal Tubular Acidosis
Type 1 RTA can develop if a person has a family history of the disease. But while genetics play a role in whether or not someone may get this disease during the course of their life, there are other factors that may lead to someone receiving a renal tubular acidosis diagnosis.
In general, Type 1 renal tubular acidosis occurs when the kidneys cannot properly handle the task of neutralizing acid due to a failure or defect in the area of the kidneys that handles this work. It’s not uncommon for a variety of illnesses and health issues to lead to the condition, including:
- Chronic hepatitis
- Chronic urinary tract infections (UTIs)
- Fabry disease
- Rejection of a transplanted kidney
- Sickle cell disease
- Sjogren’s syndrome
- Wilson disease
Medications, such as painkillers, lithium, and some anti-fungals can also lead to cases of Type 1 renal tubular acidosis.
Causes of Type 2 Proximal Renal Tubular Acidosis
Type 2 RTA, like Type 1, can be impacted by a patient’s family health history; there is a known genetic link between a parent having the condition and a child developing the condition at some point in their lifetime. Still, there are other causes for why Type 2 renal tubular acidosis occurs, including:
- Taking medications for chemotherapy
- As a side effect of other diseases, such as cystinosis, hereditary fructose intolerance, and Wilson disease
In most cases, Type 2 renal tubular acidosis occurs in children as a symptom of Fanconi’s syndrome, which impacts potassium levels, creates vitamin D deficiency, and forces the body to get rid of necessary amino acids, sugars, and other nutritional needs.
Causes of Type 4 Proximal Renal Tubular Acidosis
Type 4 RTA occurs when the kidneys have difficulty — or stop — removing excess electrolytes from the body through urination. This can happen when the body has low blood levels of aldosterone, a hormone that regulates salt and water.
According to the National Institutes of Health, Type 4 renal tubular acidosis can also happen as a side effect of certain prescribed medications or hereditary conditions.
Inherited health conditions that can cause Type 4 RTA include:
- Addison’s disease
- HIV or AIDS
- Kidney transplant rejection
- Sickle cell disease
There are several kinds of medications that can play a role in developing Type 4 renal tubular acidosis:
- ACE inhibitors and blood pressure medications
- Heparin and medications that prevent blood clotting
- Medications for congestive heart failure
- NSAID painkillers
- Some antibiotics, including trimethoprim and pentamidine
If you believe that you may have inherited the gene mutation linked to RTA and also have one of these health conditions or are using these medications, speaking with your doctor can help you determine the best course of action in preventing or reducing your risk of renal tubular acidosis.
Diagnosis of Renal Tubular Acidosis
Because renal tubular acidosis is a rare disease, it can take a variety of tests and symptom checking to determine that the condition is indeed what a patient has.
But, because the condition has some distinct symptoms, it can be more easily identified than other rare illnesses.
How do you diagnose renal tubular acidosis?
Certain symptoms can be attributed to RTA, which doctors will use when determining if a patient has the condition. Common symptoms of renal tubular acidosis include:
- Bone pain
- Confusion or a decrease in alertness
- Faster breathing
- Kidney stones
- Lessened urination
- Muscle cramps and weakness
- Pain in the back or stomach
- Slowed growth (in children)
How do doctors test for renal tubular acidosis?
Doctors are able to perform basic tests to make a renal tubular acidosis diagnosis. Medical professionals will use blood and urine samples to check the level of acidity in the blood.
Further testing into potassium, chloride, and sodium levels usually follows so that doctors can make a definitive diagnosis. In some cases, X-rays, ultrasounds, or CT scans are also used to determine if a patient has calcium deposits on the kidneys or kidney stones.
Renal Tubular Acidosis Genetics
Genetic testing to determine if someone has an increased risk of developing RTA relies on tests to detect mutations in the SLC4A1 gene.
Genetic tests for renal tubular acidosis — are they available?
Popular at-home DNA test kits aren’t yet able to determine if you carry the SLC4A1 gene mutation that can lead to the development of renal tubular acidosis. The best place to seek out a genetic test for RTA is through a doctor’s office.
After obtaining a blood sample and sending it off to a laboratory for evaluation, doctors can determine if the gene, which is located on chromosome 17, has mutations that are related to RTA.
DNA testing to spot or detect renal tubular acidosis early
There is no DNA test for renal tubular acidosis that will give 100 percent accuracy that someone will develop the condition. In fact, no DNA test can tell you for certain that you will or won’t develop a certain kind of inherited genetic condition.
Still, people with family histories of RTA may seek out a DNA test through their doctor’s office to determine if they carry mutations in the SLC4A1 gene, which can help them understand their risk. Having this kind of genetic information can help potential carriers of these gene mutations make health and medication choices that potentially reduce the risks of getting RTA.
DNA Tests Currently Available For Renal Tubular Acidosis
If you are interested in having a DNA test performed to understand your risk of renal tubular acidosis, you should know that the most common option is a blood DNA test performed at your doctor’s office.
No at-home consumer DNA test kits currently test for mutations in genes related to renal tubular acidosis.
Where can I go for a genetic test for my child?
Because there are no at-home genetic tests for renal tubular acidosis, the best way to get your child tested for this genetic mutation is through a doctor. Your child’s doctor will be able to best determine their risk of developing RTA and can also walk you through the results of the genetic test, which can help you understand the condition and preventative health measures.
DNA Testing for Renal Tubular Acidosis: Strengths and Limitations
As with most kinds of DNA testing, the biggest limitation of a test to detect renal tubular acidosis is that results can only highlight whether or not you have a genetic mutation that could increase your risk of developing the disease.
Still, a major strength is being able to know whether this potential gene mutation exists for you, and using that information to make medical decisions that reduce the risk of developing RTA.
How is renal tubular acidosis inherited?
While many cases of renal tubular acidosis are linked to medication use or as a symptom or side effect of another health condition, there is a genetic component involved in the condition. Researchers have linked renal tubular acidosis to a genetic mutation in the SLC4A1 gene, which is passed from parent to child, though there’s still much to learn about how the gene increases the chances of having RTA.
What Are The Chances That I Will Pass Renal Tubular Acidosis On To My Child?
Only one parent needs to have the SLC4A1 gene mutation to pass it onto their child.
This means that in families where only one parent is a carrier of this variation, a child has a 50 percent chance of also being born with the same mutation.
Testing for Renal Tubular Acidosis During Pregnancy Or Before Pregnancy Is Achieved
For prospective parents who are considering a DNA test to determine their child’s risk of developing renal tubular acidosis, you should know that no DNA test can definitively tell you if your child will develop this condition in their lifetime.
DNA tests to detect a parent’s gene mutation can be performed before or during pregnancy. Unfortunately, limitations in DNA testing make it difficult for soon-to-be parents to have their unborn child’s DNA tested, though if a doctor believes this information is important to know, DNA tests for renal tubular acidosis gene mutations can be performed after birth.
Who Does Renal Tubular Acidosis Typically Affect?
According to ERA-DETA, renal tubular acidosis is a relatively rare disease.
In fact, only about 1 in 100,000 people have Type 1 renal tubular acidosis. Anyone can develop renal tubular acidosis — males and females, and people of all ages. The condition also occurs in infants or babies.
Does renal tubular acidosis occur in children?
According to the Riley Children’s Health at the Indiana University Health hospital, Type 2 renal tubular acidosis often occurs in infants as part of a condition called Fanconi syndrome. Still, other forms of renal tubular acidosis are possible in all age groups depending on risk factors, such as medication use and other health conditions.
Renal Tubular Acidosis Treatment Options
It is important to seek medical attention immediately if you believe that you may have symptoms of renal tubular acidosis.
While the overall prognosis for the condition is good, it is important to alleviate your body’s building acid levels as soon as possible.
Is renal tubular acidosis treatable?
Yes, renal tubular acidosis is fully treatable, with most people making a rapid recovery. For some people, who either delay treatment or have a severe case of the condition, it is possible to have major organ damage, such as respiratory or kidney failure.
Initially, treatment consists of quickly working to lower and balance the body’s blood acidity. From there, long-term treatment options focus on regularly working to lower the body’s blood acidity, often through medications such as potassium citrate, sodium bicarbonate or some diuretics.
For other patients of RTA, restricting their intake of potassium and making changes to medications that trigger renal tubular acidosis can be enough of a long-term treatment plan.
The Prognosis for Renal Tubular Acidosis
If you’ve been diagnosed with renal tubular acidosis, you should know that the prognosis for most cases is good.
Most people, children included, who are diagnosed with renal tubular acidosis are able to make a full recovery thanks to medications that help reduce the acidity of their blood. In some cases, renal tubular acidosis that has occurred for some time without medical attention can cause further complications with the kidneys, though the overall prognosis is positive.
Does Renal Tubular Acidosis Go Away?
People facing a renal tubular acidosis diagnosis wonder if they will have this condition for life.
Cases vary from person to person, with renal tubular acidosis being a chronic, upfront health condition for some people, while others are able to easily manage it to prevent recurrences. Outcomes for people living with renal tubular acidosis are generally positive, though they may require some dietary changes.
Is there a cure for renal tubular acidosis? What are renal tubular acidosis care options?
Depending on the cause, it is possible to cure renal tubular acidosis flare ups in that treating the disease eliminates the symptoms and balances the body’s acid levels. For people with Type 1 and Type 2 renal tubular acidosis, they may be prescribed daily medications that continue to help neutralize acids within their body.
For people with Type 4 renal tubular acidosis, the disease severity may be so mild that minor adjustments to diet and medications can manage the disease and prevent flare ups.