Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

Classic Bartter syndrome

Classical Bartter syndrome is an autosomal recessive disease, which occurs in infancy. Its symptoms consist in hypokalemia, alkalosis, secondary hyperaldosteronism and hypotension due to renal salt wasting.

Historical Aspects

This subtype of barter-syndrome almost represents the 2 cases originally described by Bartter in 1962.

Epidemiology

Prevalence as in all salt wasting tubulopathies is not exactly determined. It is assumed between 1:50,000 and 1:100,000.

Clinical Findings

The clinical picture is variable. Early onset with life-threatening hypokalemia and hyponatremia is possible as well as mild cases that are only revealed by family screening. Usually, manifestation happens in infancy. Patients fail to thrive and show electrolyte disturbances. Sometimes, besides hypokalemia and hyponatremia, low plasma magnesium levels can be measured. Renal calcium excretion is only slightly altered, so nephrocalcinosis is rare.

Diagnosis

Because hypokalemia and alkalosis are present in various salt-wasting disorders, diagnosis predominantly relies on ruling out Gitelman syndrome and the other types of Bartter syndrome. Molecular genetic analysis is of particular help, especially in uncertain cases with mixed clinical symptoms and a possibly compound heterozygous genotype.

Differentials

Gitelman syndrome and the other types of Bartter syndrome are the main differentials. Age of onset, serum magnesium levels, urine excretion of calcium and prostaglandins along with a therapeutic trial with indometazine might be particularly helpful in differentiating.

Pathogenesis

The disease is caused by loss-of-function mutations in chloride channel B, which is located in the thick ascending limb of the loop of Henle.

Systematic

Bartter syndrome
Antenatal Bartter syndrome type 1
Antenatal Bartter syndrome type 2
Classic Bartter syndrome
CLCNKB
Hypercalciuric hypocalcemia 1
Hypercalciuric hypocalcemia 2
Infantile Bartter syndrome with deafness type 4
Transient antenatal Bartter syndrome

References:

1.

BARTTER FC et al. (1962) Hyperplasia of the juxtaglomerular complex with hyperaldosteronism and hypokalemic alkalosis. A new syndrome.

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2.

OMIM.ORG article

Omim 607364 [^]
3.

Orphanet article

Orphanet ID 93605 [^]
Update: May 9, 2019