Published: 2015-09-30 years Updated: 2021-07-27
Author: Thomas C. Weiss | Contact: Disabled-World.com
Peer-reviewed publications: N / A
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Summary: Information regarding Cystinuria, an inherited disease that causes the amino acid cysteine stones to form in the bladder, kidneys, and urethra. While cystinuria is a lifelong condition, symptoms usually first appear in young adults in their 20s and 30s. Symptoms can sometimes be bothersome. When an affected person does not have any stones, it is considered ‘asymptomatic’, which means it causes no symptoms. The symptoms; however, will recur every time a stone forms in the person’s kidney.
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Main announcement
Cystinuria is an inherited form of the disease that causes stones made up of the amino acid, ‘cysteine,’ to form in a person’s bladder, kidneys, and urethra. ‘Inherited’ means that the disease is passed from parents to their children through a defect in their genes. To get cystinuria, a person must inherit the defect from both their parents.
The defect in the gene causes cysteine to build up inside a person’s kidneys, which are organs that help regulate what goes in and out of a person’s blood stream. The kidneys have a number of functions, including reabsorbing essential proteins and minerals back into a person’s body, filtering their blood to remove toxic waste, as well as producing urine so that the person can excrete waste from the body.
Instead of returning to the person’s bloodstream, the amino acid cysteine is expected to build up and form stones. The stone can then get stuck in the person’s bladder, kidneys, and urethra; something that can be very painful until the stone passes through the urinary tract. Larger stones may need to be surgically removed. Stones can recur many times; however, treatments are available to control pain and help prevent more stones from forming.
Causes of Cystinuria
Defects or ‘mutations’ in the genes called ‘SLC7A9’ and ‘SLC3A1’ cause cystinuria. The genes that provide instructions for a person’s body to make a certain carrier protein are found in the kidneys. Protein normally controls the reabsorption of certain amino acids.
Amino acids are formed when a person’s body digests and breaks down proteins. Amino acids are used to perform a number of bodily functions. They are important to a person’s body and are not considered waste. As they enter the patient’s kidneys, the amino acids are normally absorbed back into the bloodstream. In people with cystinuria, their genetic defect interferes with the transport protein’s ability to reabsorb amino acids.
One of the amino acids, ‘cysteine,’ is not very soluble in a person’s urine. If it is not reabsorbed, it builds up inside the person’s kidneys and forms cysteine stones. Then, the hard, rock-like stones get stuck in the bladder, kidneys, and urethra, which can be painful. A person is only at risk for cystinuria if both their parents have the specific defect in the gene that causes their disease. Cystinuria occurs in about 1 in 10,000 people worldwide.
Symptoms of Cystinuria
While cystinuria is a lifelong condition, symptoms usually first appear in young adults in their 20s and 30s. Symptoms can sometimes be bothersome. Symptoms may include the following.
- There is blood in the urine
- Nausea and vomiting
- Pain near the pelvis, groin, or abdomen
- Severe pain in the back or side, almost always on one side
When an affected person does not have any stones, it is considered ‘asymptomatic’, which means it causes no symptoms. The symptoms; however, will recur every time a stone forms in the person’s kidney. The stones usually return more than once.
Diagnosis of cystinuria
Cystinuria is usually diagnosed when a person experiences an episode of cysteine stones. The diagnosis is then made by testing the stones to find if they are made of cysteine. Further diagnostic testing may include the following.
24 hour urine collection:
An affected person will be asked to collect their urine in a cup over the course of a day. The urine is then sent to a laboratory for analysis.
Abdominal computed tomography (CT) scan:
An abdominal computed tomography (CT) scan is an imaging method that uses X-rays to create images of structures inside a person’s abdomen to look for stones inside the kidneys.
Intravenous urography:
Conical angiography is an X-ray of a patient’s bladder, kidneys, and urethra to look for the presence of stones. This method uses a dye in the person’s blood to help visualize the stones.
Urinalysis:
A urinalysis is an examination of a person’s urine in a laboratory, something that may include looking at the shape and color of the person’s urine, viewing the urine under a microscope, as well as conducting chemical tests to detect certain substances such as cysteine.
Treatment of Cystinuria
Treatment for cystinuria is aimed at preventing stone formation. Treatment may include a number of different approaches. Possible approaches include the following.
Dietary changes:
Reducing salt intake to less than 2 grams per day has been shown to be helpful in preventing stone formation.
Increase water intake:
Drinking plenty of water is important to reduce cysteine levels in a person’s urine. According to a study from 2006 in the journal European Urology, hydration by itself can prevent the re-occurrence of stones in about 30% of those affected.
Adjust pH balance:
Cysteine is more soluble in urine at higher pH, which is a measure of how acidic or basic a substance is. Alkalinizers such as potassium citrate will raise the pH of a person’s urine to make cysteine more soluble. Some alkylating drugs can be purchased over-the-counter. It is strongly recommended; however, the person contacts their doctor before taking any type of supplement.
Medicine:
The drugs are called ‘chelators’, which help dissolve the cysteine crystals. The drug works by chemically combining with cysteine to form a complex that can then be dissolved in a person’s urine. Examples of these drugs include D-Penicillamine and alpha-mercaptopropionylglycine. D-Penicillamine works well, although it has some side effects. Pain relievers may also be prescribed to control pain as the stone passes through the affected person’s bladder and out of their body.
Surgery:
If the stones are painful and very large, or block one of the tubes leading from the kidney, they may need to be surgically removed. There are several different types of surgery to break up stones, including percutaneous nephrolithectomy, which is a procedure that involves inserting an instrument through the person’s skin and into their kidney to remove or break the stone. they. Another procedure is extracorporeal shockwave lithotripsy, which is a procedure that uses shock waves to break large stones into smaller ones.
If cystinuria is not treated appropriately, it can be extremely painful and can lead to serious complications. Complications may include the following:
- Kidney infection
- Urinary tract infections
- Bladder or kidney damage caused by stones
- Blockage of the ureter, which is the tube that carries urine from a person’s kidneys to their bladder
Cystinuria is a lifelong condition; however, it can be effectively managed with treatment. The stones themselves appear more commonly in young adults under 40. Cystinuria does not affect other parts of a person’s body and rarely causes kidney failure. Cystinuria cannot be prevented if a person’s parents both carry one copy of the genetic defect. Drinking plenty of water and reducing salt intake can help prevent stone formation.
Author credentials:
Thomas C. Weiss is a researcher and editor for Disabled World. Thomas attended college and university courses for a Master’s, Bachelor’s and two Associate’s degrees, as well as studying Disability Studies. As a Nursing Assistant, Thomas has supported people of many racial, religious, gender, class and age groups by providing care to people with all forms of disabilities. disability from Multiple Sclerosis to Parkinson’s; paralysis and quadriplegia for spina bifida.
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• Citation of this Page (APA): Thomas C. Weiss. (2015, September 30). Cystinuria: Symptoms, Causes, Treatment Methods. The world of people with disabilities. Accessed October 22, 2022 from www.disabled-world.com/health/cystinuria.php
• Permalinks: Cystinuria: Symptoms, Causes, Treatments
