Dent disease is an X-linked inherited condition caused by a mutation in the CLCN5 gene. The condition

is characterized by low-molecular-weight proteinuria, nephrocalcinosis, hypercalciuria, nephrolithiasis, and chronic kidney disease. The clinical presentation is often insidious with many patients remaining asymptomatic throughout childhood; however, signs and symptoms of nephrocalcinosis and hypercalciuria are not uncommon in childhood. The defect is in proximal tubular function, and occasionally glucosuria, aminoaciduria, metabolic acidosis, and hypophosphatemia may all occur as part of an associated partial Fanconi syndrome. In a minority of patients, the Dent phenotype results from a mutation in the OCRL gene (Dent 2), which is also involved in the oculocerebrorenal syndrome of Lowe. Bartter syndrome is an AZD2014 autosomal recessive condition characterized by renal salt wasting, hypokalemia, metabolic alkalosis, hypercalciuria, and normal serum magnesium levels. Children younger

than 6 years typically present with salt craving, polyuria, dehydration, emesis, constipation, and failure to thrive. Severe polyhydramnios, prematurity, and occasionally sensorineural deafness are the hallmark features. Mutations in the SLC12A, KCNJ1, and BSND genes (Bartter syndrome type I, type II, check details and type IV, respectively)

typically result in severe dysfunction of the thick ascending limb (TAL) of the loop of Henle in the neonatal period (neonatal Bartter syndrome). Mutations in the ClCKB gene (Bartter syndrome type III) usually cause milder TAL dysfunction and often present outside the neonatal period (classic Bartter syndrome). FHHNC often presents in childhood with seizures or tetany caused by hypomagnesemia. Other clinical manifestations include frequent urinary tract infections (UTI), polyuria, polydipsia, failure to thrive, nephrolithiasis, and progressive renal failure.19 FHHNC is an autosomal recessive condition caused by mutations in either the CLDN-16 or CLDN-19 genes. Homozygous CLDN-16 or -19 mutations are associated with impaired Vitamin B12 tight junction integrity in the TAL, urinary magnesium and calcium wasting, and resultant hypomagnesemia. Patients usually develop the characteristic triad of hypomagnesemia, hypercalciuria, and nephrocalcinosis. Profound visual impairment characterized by macular coloboma, significant myopia, and horizontal nystagmus can been seen in association with CLDN-19 mutations. 20 Primary dRTA is an inherited condition characterized by systemic acidosis as a result of the inability of the distal tubule to adequately acidify the urine.