Tubulopathies with hypokalemic alkalosis: Bartter and HELIX syndromes in children

Abstract

The review presents literature data on tubulopathies with hypokalemic alkalosis: Bartter and HELIX syndromes. Orphan Bartter syndrome with autosomal recessive (types I, II, III, IV, V) or X-linked recessive types of inheritance (type V) due to mutations in the SLC12A1, KCNJ1, CLCNKB, BSND, CLCNKA/CLCNKB, MAGED2 genes, causing impaired reabsorption ions K+, Na+, Cl-, Ca2+, Mg2+ in the thick ascending loop of Henle and in the distal convoluted tubule, characterized by hypokalemia, metabolic alkalosis, hyperreninemia and secondary hyperaldosteronism, high PgE2 levels against normal or low blood pressure, hyperplasia of the juxtaglomerular apparatus, nephrocalcinosis with I, II, V types. A new tubulopathy HELIX syndrome is described in detail, the name is formed by the first letters of symptoms (Hypohidrosis, Electrolyte imbalance, Lacrimal gl and dysfunction, Ichthyosis, Xerostomia), due to mutations in the CLDN10 gene encoding Claudin-10b necessary for paracellular reabsorption of Na+ in the thick ascending part of the loop of Henle and exocrine glands. HELIX syndrome is manifested by extrarenal symptoms (dysfunction of the salivary, sweat, lacrimal glands with impaired secretion of water into saliva, sweat — hypohidrosis and tears — alacrima) and renal (hypokalemia, hypermagnesemia, less often hypercalcemia, metabolic alkalosis, hypocalciuria).