Three Novel Homozygous Mutations of the SLC12A3 Gene in a Gitelman Syndrome Patient

AIM: Gitelman syndrome (GS) is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis. In this study, we investigated the clinical presentation and sequenced 26 exons of SLC12A3 gene in a patient with a clinical suspicion of GS. METHODS: Clinical work-up including clinical examination, electrocardiography (ECG), chest X-ray, bone mineral density (BMD), and ultrasound examination was conducted and all exons of SLC12A3 gene were analyzed by whole-exome sequencing. RESULTS: The patient showed hypokalemia, hypomagnesemia, and metabolic alkalosis and was found to have four novel homozygous missense mutations including one known mutation (c.1456 G>A in exon 12) and three novel mutations (c.366A > G in exon 2, c.791C > G in exon 6 and c.1027C > T in exon 8). CONCLUSION: Four mutation sites of SLC12A3 gene were found in the patient, three of which have not been reported before. These results may be useful for better understanding the function of this gene and can assist clinicians with treatment decision-making.