Bartter syndrome
From Wikipedia, the free encyclopedia
| ICD-10 | E26.8 |
|---|---|
| ICD-9 | 255.13 |
| OMIM | 601678 241200 607364 602522 |
| DiseasesDB | 1254 |
| eMedicine | med/213 ped/210 |
| MeSH | D001477 |
Bartter syndrome is a rare genetic disease characterized by low potassium levels (hypokalemia), decreased acidity of blood (alkalosis), and normal to low blood pressure. There are two types of Bartter syndrome: neonatal and classic. A closely associated disorder, Gitelman syndrome, is milder than both subtypes of Bartter syndrome.
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[edit] Features
In 90% of cases, neonatal Bartter syndrome is seen between 24 and 30 weeks of gestation with excess amnionic fluid (polyhydramnios). After birth, the infant is seen to urinate and drink excessively (polyuria, and polydipsia, respectively). Life-threatening dehydration may result if the infant does not receive adequate fluids. About 85% of infants dispose of excess amounts of calcium in the urine (hypercalciuria) and kidneys (nephrocalcinosis), which may lead to kidney stones. In rare occasions, the infant may progress to renal failure.
Patients with classic Bartter syndrome may have symptoms in the first two years of life, but they are usually diagnosed at school age or later. Like infants with the neonatal subtype, patients with classic Bartter syndrome also have polyuria, polydipsia, and a tendency to dehydration, but normal or just slightly increased urinary calcium excretion without the tendency to develop kidney stones. These patients also have vomiting and growth retardation. Kidney function is also normal if the disease is treated(Rodriguez-Soriano, 1998), but occasionally patients proceed to end-stage renal failure.
[edit] Diagnosis
The clinical findings characteristic of Bartter syndrome are hypokalemia, metabolic alkalosis, and normal to low blood pressure. These findings may also be caused by:
- Chronic vomiting: These patients will also have low urine chloride levels
- Abuse of diuretic medications (water pills): The physician must screen urine for multiple diuretics before diagnosis is made.
- Magnesium deficiency: These patients will also have low serum and urine magnesium
Patients with Bartter syndrome may also have elevated renin and aldosterone levels (Bartter et al, 1962)
[edit] Pathophysiology
Bartter syndrome is caused by mutations of genes encoding proteins that transport ions across renal cells (Rodriguez-Soriano, 1998). Bartter and Gitelman syndromes can also be divided into different subtypes based on the genes involved (Naesens et al, 2004)
[edit] Treatment
While patients should be encouraged to include liberal amounts of sodium and potassium in their diet, potassium supplements are usually required, and spironolactone is also used to reduce potassium loss. Nonsteroidal antiinflammatory drugs (NSAIDs) can be used as well, and are particularly helpful in patients with neonatal Bartter's syndrome. Angiotensin-converting enzyme (ACE) inhibitors can also be used.
[edit] Prognosis
[edit] Prevention
No prevention is available for this genetic disorder.
[edit] Epidemiology
[edit] History
Bartter syndrome was first described in an article by Bartter et al in 1962.
[edit] Related conditions
- Bartter and Gitelman syndromes are both characterized by hypokalemia, normal to low blood pressure, and hypochloremic metabolic alkalosis (Gitelman et al, 1966)
[edit] References
- Bartter FC, Pronove P, Gill JR Jr, MacCardle RC (1962). "Hyperplasia of the juxtaglomerular complex with hyperaldosteronism and hypokalemic alkalosis. A new syndrome". Am J Med 33: 811-28. PMID 13969763.
- Gitelman HJ, Graham JB, Welt LG (1966). "A new familial disorder characterized by hypokalemia and hypomagnesemia". Trans Assoc Am Physicians 79: 221-35. PMID 5929460.
- Naesens M, Steels P, Verberckmoes R, Vanrenterghem Y, Kuypers D (2004). "Bartter's and Gitelman's syndromes: from gene to clinic". Nephron Physiol 96 (3): p65-78. PMID 15056980.
- Rodriguez-Soriano J (1998). "Bartter and related syndromes: the puzzle is almost solved". Pediatr Nephrol 12 (4): 315-27. PMID 9655365.
