Bartter-like syndrome encompasses a set of inherited renal tubular disorders 
associated with hypokalemic metabolic alkalosis, renal salt wasting, 
hyperreninemic hyperaldosteronism, and normal blood pressure. Antenatal Bartter 
syndrome, a subtype of Bartter-like syndrome, is characterized by 
polyhydramnios, premature delivery, life-threatening episodes of fever and 
dehydration during the early weeks of life, growth retardation, hypercalciuria, 
and early-onset nephrocalcinosis. Mutations in the bumetanide-sensitive Na-K-2Cl 
cotransporter (NKCC2) and ATP-sensitive inwardly rectifying potassium channel 
(ROMK) of the thick ascending limb of Henle's loop have been identified in the 
antenatal Bartter syndrome. We report the identification of two heterozygous 
mutations of the gene for Kir 1.1 (ROMK) from an antenatal Bartter syndrome 
patient who presented at birth with mild salt wasting and a biochemical findings 
that mimicked primary pseudohypoaldosteronism type 1, such as hyperkalemia and 
hyponatremia, and evolved to a relatively benign course. We have identified 
amino acid exchanges Arg338Stop and Met357Thr in the gene exon 5 for ROMK by PCR 
and direct sequencing. Both mutations alter the C-terminus of the ROMK protein, 
and can affect channel function.