Table 3.

Classification of Bartter syndrome

Types of Bartter syndrome	Defective gene
Type I (Neonatal)	Na-K 2 Cl channel mutation
Type II (Neonatal)	Apical K channel mutation
Type III (Classic)	Basolateral Cl channel mutation
Type IV (Neonatal with SNHL)	Basolateral Cl channel mutation (β subunit)
Type V (Classic)	Gain of function in CaSR

Based on defect on any of the below mentioned channels BS has been classified into five types. Mostly BS presents in neonatal period except type V which presents in adolescents and early adulthood