Bartter Disease Type 2
Disease Details
Family Health Simplified
- Description
- Bartter disease type 2 is an inherited disorder characterized by disrupted salt reabsorption in the kidneys, leading to an imbalance of electrolytes and presenting in infancy with severe symptoms like hypokalemia, alkalosis, and hypercalciuria.
- Type
- Bartter syndrome type 2 is an autosomal recessive disorder.
- Signs And Symptoms
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Bartter syndrome type 2 is a rare inherited disorder that affects the kidneys' ability to reabsorb sodium. Signs and symptoms typically include:
- Hypokalemia (low potassium levels)
- Metabolic alkalosis (elevated blood pH)
- Hypercalciuria (high calcium levels in the urine)
- Growth retardation
- Muscle weakness
- Polyuria (excessive urination)
- Polydipsia (excessive thirst)
- Nephrocalcinosis (calcium deposits in the kidneys)
Infants may present with dehydration, vomiting, and failure to thrive. Early diagnosis and treatment are crucial for managing symptoms and preventing complications. - Prognosis
- Bartter syndrome type 2, a rare inherited renal tubular disorder, often manifests in infancy. The prognosis varies considerably based on factors such as early diagnosis and management. With appropriate treatment, including supplementation of electrolytes and medications like potassium-sparing diuretics, patients can manage symptoms effectively. However, there is a potential risk for complications such as growth delay and chronic kidney disease. Lifelong monitoring is typically required.
- Onset
- Bartter syndrome type 2 typically presents with symptoms in the neonatal period. This can include polyhydramnios (excessive amniotic fluid during pregnancy), premature birth, failure to thrive, and electrolyte imbalances such as low potassium (hypokalemia) and elevated blood pH (metabolic alkalosis).
- Prevalence
- The prevalence of Bartter Syndrome Type 2 is not well established and is considered extremely rare.
- Epidemiology
- Bartter syndrome type 2 is a rare inherited renal disorder caused by mutations in the KCNJ1 gene, which encodes the renal outer medullary potassium (ROMK) channel. Exact epidemiological data like prevalence or incidence rates for Bartter syndrome type 2 specifically is limited due to its rarity and the broader classification often used for Bartter syndromes as a group. It is generally considered an autosomal recessive disorder, meaning it affects individuals who inherit two defective copies of the gene, one from each parent.
- Intractability
- Bartter syndrome type 2, like other forms of Bartter syndrome, is considered a chronic condition that requires ongoing management. It affects the kidneys' ability to reabsorb salt, leading to imbalances in electrolytes and fluid. While there are treatments available to manage symptoms, such as potassium supplements and medications to reduce urine output, there is currently no cure. Therefore, Bartter syndrome type 2 is considered intractable as it requires lifelong management but cannot be completely eradicated.
- Disease Severity
- Bartter disease type 2 typically presents with severe symptoms in infancy. Affected individuals often suffer from life-threatening episodes of dehydration, low levels of potassium (hypokalemia), and chloride in the blood (hypochloremia). Other complications can include metabolic alkalosis, growth delays, and muscle weakness. Without timely medical intervention, the condition can be quite severe, particularly in the early stages of life.
- Healthcare Professionals
- Disease Ontology ID - DOID:0110143
- Pathophysiology
- Bartter disease type 2 is an inherited renal tubular disorder characterized by mutations in the ROMK (Kir1.1; gene KCNJ1) channel, which plays a critical role in potassium ion transport in the thick ascending limb of the loop of Henle. These mutations impair potassium recycling and disrupt the function of the Na-K-2Cl cotransporter. This results in impaired sodium reabsorption, leading to salt wasting, hypokalemia, metabolic alkalosis, and secondary hyperaldosteronism. Key clinical features include polyuria, polydipsia, growth retardation, and elevated plasma renin and aldosterone levels.
- Carrier Status
- Bartter disease type 2 is an autosomal recessive disorder. This means that carriers have one copy of the mutated gene and typically do not show symptoms. The carrier rate varies depending on the population but a carrier must inherit the mutation from one parent to be a carrier. For a child to be affected by Bartter disease type 2, they must inherit two copies of the mutated gene, one from each parent.
- Mechanism
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Bartter disease type 2 is a genetic disorder affecting renal salt reabsorption, leading to issues like hypokalemia, metabolic alkalosis, and hypercalciuria. The disease specifically involves mutations in the KCNJ1 gene, encoding the renal outer medullary potassium (ROMK) channel.
Mechanism:
Bartter disease type 2 disrupts the function of the ROMK channel, which plays an essential role in potassium recycling in the renal thick ascending limb of the loop of Henle. This channel's dysfunction impairs potassium and sodium reabsorption, leading to salt wasting, increased aldosterone, and subsequent electrolyte imbalances.
Molecular Mechanisms:
The molecular basis involves mutations in the KCNJ1 gene, resulting in defective or absent ROMK channels. These mutations impede the normal function of the channel, reducing its ability to facilitate potassium exit from cells into the tubular lumen. This disrupts the sodium-potassium-chloride cotransport mechanism, impairing overall salt reabsorption and causing the clinical symptoms observed in Bartter disease type 2. - Treatment
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Bartter disease type 2 is a rare inherited disorder affecting renal function, leading to an imbalance of potassium, sodium, chloride, and other electrolytes. The treatment typically focuses on managing symptoms and may include:
- **Potassium supplements**: To correct hypokalemia.
- **Nonsteroidal anti-inflammatory drugs (NSAIDs)**: Such as indomethacin, to reduce prostaglandin production and help with electrolyte balance.
- **Magnesium supplements**: To address hypomagnesemia if present.
- **ACE inhibitors or ARBs**: To reduce urinary potassium loss.
Additionally, maintaining a diet rich in potassium and monitoring electrolyte levels regularly is important in managing the condition effectively. - Compassionate Use Treatment
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Bartter Syndrome Type 2 is a rare inherited renal disorder characterized by disrupted potassium and chloride transport in the kidneys. While there is no cure, various off-label treatments and experimental therapies may be considered to manage symptoms and improve quality of life.
1. **Potassium and Magnesium Supplements**: To correct hypokalemia and hypomagnesemia.
2. **Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)**: Such as indomethacin, to reduce prostaglandin production and help with electrolyte balance.
3. **Potassium-Sparing Diuretics**: Such as spironolactone or amiloride, to help reduce potassium loss.
4. **ACE Inhibitors or ARBs**: These medications can help manage hypertension.
5. **Experimental Therapies**: Research is ongoing into gene therapy and other molecular approaches, but these are not yet standard treatments.
Compassionate use may allow access to experimental drugs in certain severe cases, but this is typically considered on a case-by-case basis under strict regulatory supervision. - Lifestyle Recommendations
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For Bartter disease type 2, lifestyle recommendations generally focus on managing symptoms and improving quality of life. These may include:
1. **Regular Monitoring**: Frequent check-ups with healthcare providers to monitor electrolyte levels and kidney function.
2. **Medication Adherence**: Strict adherence to any prescribed medications, such as potassium supplements, to manage electrolyte imbalances.
3. **Hydration**: Ensuring adequate fluid intake to prevent dehydration, especially since this condition can lead to fluid imbalances.
4. **Balanced Diet**: Consuming a diet rich in potassium and low in sodium may help manage electrolyte levels.
5. **Avoiding Dehydrating Activities**: Limiting exposure to heat or intensive physical activities that can lead to excessive sweating and further electrolyte loss.
6. **Prenatal Care**: For pregnant women with a history of Bartter syndrome, close monitoring and care during pregnancy are crucial.
7. **Support Groups/Counseling**: Engaging in support groups or counseling for emotional and psychological support.
Always consult with healthcare providers for personalized recommendations based on individual health status. - Medication
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Bartter syndrome type 2, a rare inherited condition affecting the kidneys, often requires careful medical management. Given its complexity, treatment focuses on maintaining electrolyte balance and managing symptoms. Medications commonly used include:
- **Potassium-sparing diuretics** (e.g., spironolactone or amiloride) to help conserve potassium levels.
- **Nonsteroidal anti-inflammatory drugs (NSAIDs)** (e.g., indomethacin) to reduce prostaglandin production, which may help with fluid and electrolyte balance.
- **Potassium supplements** to address hypokalemia (low potassium levels).
- **Magnesium supplements** if hypomagnesemia (low magnesium levels) is present.
- **ACE inhibitors or angiotensin receptor blockers (ARBs)** to manage hyperreninemic hyperaldosteronism.
Regular monitoring by a healthcare provider is essential to adjust treatments based on the patient's ongoing needs. - Repurposable Drugs
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Repurposable drugs for Bartter syndrome type 2 include:
1. **Indomethacin**: A nonsteroidal anti-inflammatory drug (NSAID) that can help manage electrolyte imbalances by reducing prostaglandin synthesis.
2. **Spironolactone**: A potassium-sparing diuretic that can help counteract hypokalemia and hyperaldosteronism.
3. **Amiloride**: Another potassium-sparing diuretic that can be used to address hypokalemia.
4. **Angiotensin-converting enzyme (ACE) inhibitors**: These can help manage hypertension and reduce aldosterone levels.
These repurposed drugs help manage the symptoms and complications associated with Bartter syndrome type 2. - Metabolites
- Bartter disease type 2 is characterized by a disruption in potassium, sodium, and chloride reabsorption in the kidneys due to mutations in the ROMK (KCNJ1) gene. This leads to various metabolic imbalances, including hypokalemia (low potassium levels), metabolic alkalosis (elevated blood pH due to bicarbonate excess), and elevated levels of renin and aldosterone. Specific metabolites directly affected include potassium and chloride, along with secondary effects on sodium, calcium, and magnesium levels.
- Nutraceuticals
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Bartter syndrome type 2 is a rare inherited disorder that affects the kidneys' ability to reabsorb salts. Nutraceuticals and dietary supplements can sometimes be used as supportive treatments alongside conventional therapies, but specific recommendations should always be personalized and guided by a healthcare professional. Key considerations generally include:
1. **Electrolyte Supplements**: Potassium and magnesium supplements may be needed to counteract the characteristic potassium and magnesium loss.
2. **Salt Supplementation**: Sodium chloride (table salt) supplements can help manage dehydration and electrolyte imbalance.
3. **Water-Soluble Vitamins**: Supplementation with water-soluble vitamins like vitamin C and B vitamins might be beneficial since patients have altered renal handling of various nutrients.
There is no well-established role for nanotechnology-based nutraceuticals in the current management of Bartter syndrome type 2. Always consult a healthcare provider before starting any new treatment or supplement. - Peptides
- Bartter disease type 2 is caused by mutations in the KCNJ1 gene, which encodes the ROMK (Renal Outer Medullary Potassium) channel. This channel is crucial for potassium recycling in the renal tubules, specifically in the thick ascending limb of the loop of Henle. Peptides relevant to Bartter disease type 2 are not specifically used in the standard diagnosis or treatment, as the focus is primarily on genetic testing to confirm the mutation and management of electrolyte imbalances. Management typically includes supplementation of potassium, sodium, and magnesium, along with nonsteroidal anti-inflammatory drugs (NSAIDs) or potassium-sparing diuretics to reduce urinary losses.