Clinical and genetic analysis of a patient with Gitelman syndrome misdiagnosed as hypokalemic periodic paralysis

OBJECTIVE To explore the genetic basis for a child suspected for hypokalemic periodic paralysis. METHODS Clinical data of the patient was collected, and venous blood samples were taken from the patient and his parents for the extraction of genomic DNA. Next generation sequencing (NGS) with target capture was carried out to detect potential variants. Suspected variants were validated by Sanger sequencing. RESULTS The child developed fatigue without obvious reason at the age of 15. Laboratory test revealed hypokalemia but normal serum magnesium. Genetic testing discovered that he has carried two variants in the SLC12A3 gene, namely c.179C>T and c.539C>A. The patient was diagnosed with Gitelman syndrome. CONCLUSION For children with hypokalemia, genetic testing should be considered for the differential diagnosis of Gitelman syndrome from hypokalemia due to other causes.