LAUSR

BACKGROUND Gitelman syndrome (GS) is an unusual, autosomal recessive salt-losing tubulopathy characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. It is caused by mutations in the solute carrier family 12 member 3 (SLC12A3) gene resulting in disordered function of the thiazide-sensitive NaCl co-transporter. To date, many types of mutations in the SLC12A3 gene have been discovered that trigger different clinical manifestations. Therefore, gene sequencing should be considered before determining the course of treatment for GS patients. CASE SUMMARY A 55-year-old man was admitted to our department due to hand numbness and fatigue. Laboratory tests after admission showed hypokalemia, metabolic alkalosis and renal failure, all of which suggested a diagnosis of GS. Genome sequencing of DNA extracted from the patient’s peripheral blood showed a rare homozygous mutation in the SLC12A3 gene (NM_000339.2: chr16:56903671, Exon4, c.536T>A, p.Val179Asp). This study reports a rare homozygous mutation in SLC12A3 gene of a Chinese patient with GS. CONCLUSION Genetic studies may improve the diagnostic accuracy of Gitelman syndrome and improve genetic counseling for individuals and their families with these types of genetic disorders