Gitelman syndrome caused by a rare homozygous mutation in the SLC12A3 gene:A case report

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 thiazidesensitive 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.