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Cystinuria
Cystinuria is an inherited condition characterized by a buildup of the amino acid, cystine, in the kidneys and bladder
Prevalence
1-5 / 10 000
Age of Onset
ICD-10
E72.0
Inheritance
Autosomal dominant
Autosomal recessive
Mitochondrial/Multigenic
X-linked dominant
X-linked recessive
Rare View
Cystinuria is a rare condition in which stones made from an amino acid called cysteine form in the kidney, ureter, and bladder. Cystinuria is caused by mutations in the SLC3A1 and SLC7A9 genes. Mutations in either of these genes disrupt the ability of this transporter protein to reabsorb these amino acids, allowing them to become concentrated in the urine. As the levels of cystine in the urine increase, it forms cystine crystals, resulting in kidney stones. Cystine crystals form hexagonal-shaped crystals that can be viewed upon microscopic analysis of the urine. People with cystinuria pass stones monthly, weekly, or daily, and need ongoing care.†
5 Facts you should know
FACT
Cystinuria is characterized by the inadequate reabsorption of cystine in the proximal convoluted tubules
FACT
This leads to the formation of cystine crystals and/or stones which may block the urinary tract
FACT
Signs and symptoms of the condition are related to the presence of stones and may include nausea, hematuria, flank pain, and/or frequent urinary tract infections
FACT
It is usually an inherited condition characterized by a buildup of cystine in the kidneys and bladder
FACT
Cystinuria is caused by changes (mutations) in the SLC3A1 and SLC7A9 genes and is inherited in an autosomal recessive manner
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Common signs & symptoms
Abnormality of amino acid metabolism
Hematuria
Blood in urine
Nephrolithiasis
Kidney stones
Hyperuricemia
High blood uric acid level
Renal insufficiency
Renal failure
Abnormality of the nervous system
Neurologic abnormalities
Argininuria
High urine arginine levels
Current treatments
Treatment of cystinuria is focused on relieving symptoms and preventing the formation of additional stones. A more conservative approach is typically tried first. This may include increasing fluid intake, regular monitoring of urinary pH, dietary restrictions (i.e. eating less salt) and increasing the pH of urine with potassium citrate supplements. If these strategies do not prevent the formation of stones, medications may be added to help dissolve the cystine crystals.[1][2][3]
Treatment for cystinuria-related stones varies depending on the size and location of the stone, but may include:[1][2][3]
- Extracorporeal shock wave lithotripsy (ESWL)
- Ureteroscopy
- Percutaneous nephrolithotomy
- Open surgery (in rare cases)
Medscape Reference's Web site offers more specific information regarding the treatment and management of cystinuria. Please click on the link to access this resource.
FDA-Approved Treatments
The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.
Tiopronin
(Brand name: Thiola®) Manufactured by Retrophin, Inc.
FDA-approved indication: Prevention of cystine nephrolithiasis in patients with homozygous cystinuria.
Top Clinical Trials
Title | Description | Phases | Status | Interventions | More Information |
---|---|---|---|---|---|
Lipoic Acid Supplement for Cystine Stone | This study evaluates how daily alpha lipoic acid supplementation affects cystine kidney stone recurrence. Half of the subjects will receive 1200 mg alpha lipoic acid orally daily for three years, while the other half will receive a placebo. | Phase 2 | Active, not recruiting | Dietary Supplement: Alpha lipoic acid|Drug: Placebo | More Info |
The Effect of Sodium-glucose Cotransporter (SGLT) 2 Inhibitors on Cystine Stone Formation: A Preliminary Study | This is a single center, proof of concept prospective cohort trial designed to assess the effect of daily oral administration of dapagliflozin on cystine formation in freshly voided urine. | Phase 2 | Recruiting | Drug: Dapagliflozin | More Info |
Top Treatments in Research
Agent | Class/Mechanism of Action | Development Status | Company | Clinical Studies | More Information |
---|---|---|---|---|---|
Lipoic Acid | Lipoic acid (LA), also known as α-lipoic acid, alpha-lipoic acid (ALA) and thioctic acid, is an organosulfur compound derived from caprylic acid (octanoic acid) | Phase 2 | Thomas Chi, MD, University of California, San Francisco | More Info | More Info |
SGLT 2 Inhibitors | SGLT-2 inhibitor is an abbreviation for sodium-glucose cotransporter-2 inhibitors. SGLT-2 inhibitors are a class of medicine used to lower high blood glucose levels in people with type 2 diabetes | Phase 2 | University of California, San Francisco | More Info | More Info |
† Medline Plus, National Library of Medicine