Two Case Report Of Gitelman Syndrome And Literature Review

Objective: To summarize the clinical manifestations,laboratory examination,gene analysis,diagnosis and treatment of two patients with Gitelman syndrome(GS),and to improve the acquaintance of GS.In order to reduce misdiagnosis and missed diagnosis,and to provide a reference for making a rational individualized diagnosis and treatment plan.Methods: We retrospectively analyzed two young male patients with GS confirmed by symptoms,signs,laboratory findings,imaging examinations,and genetic testing,and reviewed the literatures concerning GS to summarize its clinical characteristics,diagnosis and treatment.for rationalization,individualized diagnosis and treatment plan.Results: Case 1,male,15 years old,juvenile onset,and diagnosed as GS about 2months later.He complained fatigue,paroxysmal headache,dizziness,numbness,twitch,unconsciousness and syncope.Blood pressure was 110/80 mmHg.Laboratory examinations showed serum potassium 2.57 mmol/L,serum magnesium 0.54 mmol/L,serum chloride 100 mmol/L,urinary potassium 42mmol/24 h,urinary calcium/creatinine0.03,fractional excretion of chloride 1.53%,arterial blood gas PH 7.446,standard bicarbonate 25.9 mmol/L,Direct Renin Concentration(DRC)165.3 μIU/ml,Plasma renin activity(PRA)3.8ng/ml/h,angiotensinⅡ(AⅡ)138.73pg/ml,aldosterone(Ald)140.32 pg/ml.Kidney ultrasound was normal.Genetic testing found two missense mutations in the exon of SLC12A3.One was in exon 12,c.1567G>A,p.Ala523Thr;the other one was in exon 15,c.1909C>T,p.His637 Tyr.Thus GS was confirmed.Wegave him potassium chloride sustained release tablets 3g/d.His symptoms were disappeared,and the serum potassium gradually increased to 3.5mmol /L.Case 2,male,36 years old,unmarried.It was characterized by flaccid paralysis of limbs,lethargy,nocturia,and decreased resistance.Hypokalemia was found in childhood.His body develops normally.The gene detection showed that SLC12A3 gene mutations in exon,thus GS was confirmed at Ruijin Hospital Affiliated to Shanghai Jiao Tong University in 2009,when he was 28 years old.The duration of GS was more than30 years.Blood pressure was 110/70 mmHg.Laboratory examination were as following,serum potassium 1.93 mmol/L,serum magnesium 0.56 mmol/L,serum chloride 96mmol/L,urinary potassium 118 mmol/24 h,urinary calcium/creatinine 0.05,fractional excretion of chloride 1.05%,arterial blood gas PH 7.459,standard bicarbonate 26.4mmol/L,DRC 426.5 μIU/ml,PRA5.25 ng/ml/h,AⅡ 90.63 pg/ml,Ald 310.14 pg/ml.Kidney ultrasound indicated right renal suspected pelvis cyst,and left kidney is normal.We gave him oral potassium and magnesium supplementation: potassium chloride sustained release tablets 4g/d,potassium magnesium aspartate 6co /d,potassium magnesium liquid 20ml/d,but serum potassium had no obvious change.So we combined oral spironolactone 60 mg/d,while serum potassium was still not improved notably,therefore,we gave him spironolactone with the dosage of 120mg/d.Two days later,serum potassium was increased to 3.2 mmol/L,and his symptoms improved.During ten days treatment,serum potassium fluctuated between 3.20~3.28mmol/L.Conclusions:1.Patients with typical clinical characteristics and laboratory examinations related to hypokalemia,hypomagnesemia,low serum chloride metabolic alkalosis,hypocalciuria,normal or low blood pressure and increase activity of RAAS are supposed to be diagnosed as GS clinically,and confirmed diagnosis relies on the SLC12A3 gene detection.All suspected patients and their first-degree relatives are recommended for genetic testing to be confirmed.2.Single Potassium or magnesium supplementation or combination is the basic treatment in patients with GS,and combined with spironolactone or eplerenone ifnecessary.3.It is helpful to recognise GS and achieve the goal of early detection,early diagnosis,early treatment,regular follow-up,standard treatment,and avoiding kidney damage.