Table 1.

Bartter's syndrome: Different types and variants

	BS type I	BS type II	BS type III	BS type IV BSND variant	Gitelman's variant
Channel	NKCC2	ROMK	CIC-Kb	CIC-Kb/CIC-Ka	NCCT
Location	TAL	TAL, CD	TAL, DCT	TAL, Inner ear	DCT
Gene	SLC12A1	KCNJ1	CLCNKB	BSND	SLC12A3
Chromosome	15q15-21	11q24	1p36	1p31	16q13
Polyhydramnios	Present	Present	Absent	Present	Absent
Gestational age	Preterm	Preterm	Near term	Preterm	Term
Age of onset	Antenatal	Antenatal	<1year	Antenatal	6–13 years
Symptoms	Polyuria	Polyuria	Hypokalemia failure to thrive	Polyuria, deafness	Hypokalemia, tetany
Urine Ca excretion	High	High	Moderate	High	Hypocalciuria
Nephrocalcinosis	Present	Present	Usually absent	Present	Absent
Magnesium	Normal	Normal	Low or normal	Normal	Always low
Prostaglandin level	Increased	Increased	Increased	Increased	Near normal
Prostaglandin excretion	Increased	Increased	Increased	Increased	Normal