Early diagnosis of Gitelman syndrome in a young child: A case report

BACKGROUND: Gitelman syndrome (GS) is an autosomal recessive renal tubular disorder characterized by renal wasting hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. It is usually caused by mutations in the gene SLC12A3, which encodes the thiazide-sensitive Na-Cl cotransporter. GS is not usually diagnosed until late childhood or adulthood. CASE SUMMARY: Here, we report the case of a one-year-old girl who was brought to the emergency department due to persistent vomiting for two days. On admission to our hospital, generalized weakness was observed, and laboratory investigations revealed severe hypokalemia (1.9 mmol/L). However, persistent hypokalemia was observed during outpatient follow-up. Suspicion of the GS phenotype was assessed via the patient’s clinical presentation, family history, and biochemical analysis of blood and urine. Further genetic analysis was performed for her and her family by exon-wide sequencing analysis of the gene SLC12A3. The genetic diagnosis of GS was established in the Taiwanese family with three affected individuals, two of whom were children (7 years/17 years) without obvious symptoms, with the youngest being only one year old (patient in our case). CONCLUSION: We successfully demonstrated the early diagnosis of GS using family genetic analysis. Any instances of hypokalemia should not be neglected, as early detection of GS with suitable treatment can prevent patients from potentially life-threatening complications.