The other subtypes of the syndrome involve mutations in other transporters that result in functional loss of the target transporter. Patients often admit to a personal preference for salty foods.The clinical findings characteristic of Bartter syndrome is hypokalemia, metabolic alkalosis, and normal to low blood pressure. These findings may also be caused by other conditions, which may cause confusion. When diagnosing a Bartters syndrome, the following conditions must be ruled out as possible causes of the symptomatology:
Chronic vomiting: These patients will have low urine chloride levels; they have relatively higher urine chloride levels. Abuse of diuretic medications  (water pills): The physician must screen urine for multiple diuretics before a diagnosis is made. Magnesium deficiency and calcium deficiency: These patients will also have low serum and urine magnesium and calcium.Patients with Bartter syndrome may also have elevated renin and aldosterone levels.Prenatal Bartter syndrome can be associated with polyhydramnios. Related conditions
Bartter and Gitelman syndromes are both characterized by low levels of potassium and magnesium in the blood, normal to low blood pressure, and hypochloremic metabolic alkalosis.However, Bartter syndrome is also characterized by high renin, high aldosterone, hypercalciuria, and an abnormal Na+-K+-2Cl− transporter in the thick ascending limb of the loop of Henle, whereas Gitelman syndrome causes hypocalciuria and is due to an abnormal thiazide-sensitive transporter in the distal segment. Pseudo-Bartters syndrome is a syndrome of similar presentation as Bartter syndrome but without any of its characteristic genetic defects. Pseudo-Bartters syndrome has been seen in cystic fibrosis, as well as in excessive use of laxatives.
Bartter syndrome (BS) is a rare inherited disease characterised by a defect in the thick ascending limb of the loop of Henle, which results in low potassium levels (hypokalemia), increased blood pH (alkalosis), and normal to low blood pressure. There are two types of Bartter syndrome: neonatal and classic. A closely associated disorder, Gitelman syndrome, is milder than both subtypes of Bartter syndrome. Signs and symptoms
In 90% of cases, neonatal Bartter syndrome is seen between 24 and 30 weeks of gestation with excess amniotic fluid (polyhydramnios). After birth, the infant is seen to urinate and drink excessively (polyuria, and polydipsia, respectively). Life-threatening dehydration may result if the infant does not receive adequate fluids. About 85% of infants dispose of excess amounts of calcium in the urine (hypercalciuria) and kidneys (nephrocalcinosis), which may lead to kidney stones. In rare occasions, the infant may progress to kidney failure.Patients with classic Bartter syndrome may have symptoms in the first two years of life, but they are usually diagnosed at school age or later. Like infants with the neonatal subtype, patients with classic Bartter syndrome also have polyuria, polydipsia, and a tendency to dehydration, but normal or just slightly increased urinary calcium excretion without the tendency to develop kidney stones. These patients also have vomiting and growth retardation. Kidney function is also normal if the disease is treated, but occasionally patients proceed to end-stage kidney failure. Bartter syndrome consists of low levels of potassium in the blood, alkalosis, normal to low blood pressures, and elevated plasma renin and aldosterone.