Transient neonatal hyperkalemia in the antenatal (ROMK defective) Bartter syndrome.
OBJECTIVE
Identification of neonatal hyperkalemia as a complication of Bartter syndrome (BS), a disorder usually characterized by hypokalemic metabolic alkalosis. Study design Case-series description of a group of 12 infants with mutations in the renal potassium channel ROMK, causing one of the antenatal variants of BS.


RESULTS
Prematurity, postnatal polyuria, and dehydration were seen in all cases. Plasma potassium was as high as 9.0 +/- 1.2 mmol/L and sodium as low as 124 +/- 3.5 mmol/L, appearing usually at day 3 of life and normalizing by the end of the first postnatal week. No hyperkalemia was found in 12 neonates with the variant of BS and deafness. The mean plasma potassium level during the first week of life among a group of very low-birth-weight infants with similar relative azotemia was 4.9 +/- 1 mmol/L (P <.001). The postneonatal period in the ROMK-defective children with BS was characterized by failure to thrive, hypercalciuria, nephrocalcinosis, and minimal-to-no hypokalemia.


CONCLUSIONS
Early postnatal hyperkalemia, sometimes severe, may complicate antenatal BS associated with ROMK mutations. Its association with hyponatremia and hyperreninemic hyperaldosteronism may erroneously suggest the diagnosis of pseudohypoaldosteronism type 1. The expression of ROMK in both the thick ascending limb and cortical collecting duct may explain this apparently tubular maturation phenomenon.
Finer
Gal
G
Departments of Pediatrics and Genetics, Soroka University Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel.
Shalev
Hanna
H
Birk
Ohad S
OS
Galron
Dalia
D
Jeck
Nikola
N
Sinai-Treiman
Levana
L
Landau
Daniel
D
D000293:Adolescent; D001477:Bartter Syndrome / Q000150:complications / Q000151:congenital* / Q000235:genetics / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D006947:Hyperkalemia / Q000150:complications*; D007223:Infant; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008297:Male; D009154:Mutation; D009397:Nephrocalcinosis / Q000150:complications; D011188:Potassium / Q000097:blood; D015221:Potassium Channels / Q000235:genetics*; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics; D014508:Urea / Q000097:blood
C086989:KCNJ1 protein, human; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D014508:Urea; D003404:Creatinine; D011188:Potassium