Early-Onset Gitelman Syndrome With Normomagnesemia and Absence of Metabolic Alkalosis: Expanding the Phenotypic Spectrum

AbstractGitelman syndrome is an autosomal recessive tubulopathy caused by SLC12A3 mutations and typically presents with hypokalemia, metabolic alkalosis, and hypomagnesemia. However, atypical phenotypes are increasingly recognized. We report a four-year-old child with recurrent hypokalemia without hypomagnesemia or metabolic alkalosis. Genetic analysis revealed compound heterozygous SLC12A3 variants, including a missense mutation and a novel frameshift mutation. This case expands the phenotypic and mutational spectrum of Gitelman syndrome and highlights that it should be considered in pediatric hypokalemia even in the absence of classical biochemical features.Keywords Gitelman syndrome; SLC12A3; hypokalemia