Hyponatremic Seizures--Presenting Symptom of Helix Syndrome.

Abstract Genetic causes of renal tubular dyselectrolytemia are primarily associated with urinary sodium loss, with secondary hypokalemic metabolic alkalosis. They may be associated with or without hypercalciuria and hypermagnesuria. HELIX syndrome (OMIM 617671) is one condition associated with hypermagnesmia and hypomagnesuria in contrast to Gitleman syndrome. The diagnosis is made if dyselectrolytemia and hypermagnesmia is accompanied with physical findings of hypohidrosis, lacrimal gland dysfunction, ichthyosis and xerostomia. This is the first case in our limited experience of a genotype of HELX syndrome presenting as hyponatremic seizures with unreported hypomagnesemia, hypermagnesuria and hypocalciuria due to defect of para-cellular ion transport in the thicker limb of ascending Henle’s loop (TAL).