Danbot: Added DDX template transclusions: Hypokalemia, Hypomagnesemia, Metabolic alkalosis, Renal tubular disorders, Prolonged QT

2026-03-19T11:31:16Z

Added DDX template transclusions: Hypokalemia, Hypomagnesemia, Metabolic alkalosis, Renal tubular disorders, Prolonged QT

← Older revision		Revision as of 11:31, 19 March 2026
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	*Hypomagnesemia from other causes: PPI use, alcoholism, aminoglycosides, cisplatin — check medication history		*Hypomagnesemia from other causes: PPI use, alcoholism, aminoglycosides, cisplatin — check medication history
	*Pseudogout (if presenting with chondrocalcinosis): check electrolytes in any young patient with calcium pyrophosphate arthropathy — may unmask Gitelman		*Pseudogout (if presenting with chondrocalcinosis): check electrolytes in any young patient with calcium pyrophosphate arthropathy — may unmask Gitelman

			{{Hypokalemia DDX}}
			{{Hypomagnesemia DDX}}
			{{Metabolic alkalosis DDX}}
			{{Renal tubular disorders DDX}}

	==Evaluation==		==Evaluation==
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	**Urine calcium:creatinine ratio LOW (hypocalciuria) — the key distinction from Bartter (which has hypercalciuria)		**Urine calcium:creatinine ratio LOW (hypocalciuria) — the key distinction from Bartter (which has hypercalciuria)
	*ECG: prolonged QT, flattened T waves, U waves, ST depression; assess for arrhythmia		*ECG: prolonged QT, flattened T waves, U waves, ST depression; assess for arrhythmia

			{{Prolonged QT DDX}}

	*Urine drug screen for diuretics — must exclude thiazide abuse before diagnosing Gitelman		*Urine drug screen for diuretics — must exclude thiazide abuse before diagnosing Gitelman

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2026-03-19T11:14:28Z

Moved intro paragraph into Background section as bullets; removed excessive bold formatting from bullet lead-in text throughout

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Ostermayer: Created page with "Gitelman syndrome is an autosomal recessive salt-losing tubulopathy caused by loss-of-function mutations in the '''thiazide-sensitive sodium-chloride cotransporter (NCC)''' in the distal convoluted tubule.Gitelman Syndrome. ''StatPearls''. NCBI. 2024. It is the '''most common inherited renal tubulopathy''' (~1 in 40,000) and presents with '''hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria''' — biochemically identical to '..."

2026-03-18T02:40:30Z

Created page with "Gitelman syndrome is an autosomal recessive salt-losing tubulopathy caused by loss-of-function mutations in the '''thiazide-sensitive sodium-chloride cotransporter (NCC)''' in the distal convoluted tubule.<ref name="StatPearls">Gitelman Syndrome. ''StatPearls''. NCBI. 2024.</ref> It is the '''most common inherited renal tubulopathy''' (~1 in 40,000) and presents with '''hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria''' — biochemically identical to '..."

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Gitelman syndrome is an autosomal recessive salt-losing tubulopathy caused by loss-of-function mutations in the '''thiazide-sensitive sodium-chloride cotransporter (NCC)''' in the distal convoluted tubule.<ref name="StatPearls">Gitelman Syndrome. ''StatPearls''. NCBI. 2024.</ref> It is the '''most common inherited renal tubulopathy''' (~1 in 40,000) and presents with '''hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria''' — biochemically identical to '''chronic thiazide diuretic use'''.<ref name="KDIGO">Gitelman syndrome: consensus and guidance from a KDIGO Controversies Conference. ''Kidney Int''. 2017;91(1):24-33.</ref> Usually diagnosed in '''adolescence or adulthood''', it is generally benign but can cause '''life-threatening hypokalemia, cardiac arrhythmias, tetany, paralysis, and rhabdomyolysis'''. The EM physician encounters Gitelman syndrome as '''unexplained refractory hypokalemia in a young normotensive patient''', '''tetany or muscle cramps''', or '''cardiac arrhythmia from combined hypokalemia and hypomagnesemia'''.

==Background==
*Prevalence ~1 in 40,000 (heterozygote carrier frequency ~1% in Caucasians); higher in Asian populations
*Much more common than [[Bartter syndrome]] (~1 in 1,000,000)
*Usually presents '''after age 6'''; most diagnosed in adolescence or adulthood — many patients are asymptomatic for years
*Mimics '''chronic thiazide (HCTZ) use''' — the NCC cotransporter is the same target as thiazide diuretics
*'''Sudden cardiac death''' has been reported from severe hypokalemia/hypomagnesemia<ref name="KDIGO"/>

==Clinical Features==
*Many patients are '''asymptomatic''' — discovered incidentally on routine labs showing hypokalemia
*'''Muscle cramps, weakness, fatigue''' — the most common complaints
*'''Tetany, carpopedal spasm''' — from hypomagnesemia; especially during illness or with vomiting/diarrhea
*'''Facial paresthesias''' — characteristic
*'''Salt craving''' (sometimes intense; also craving sour foods)
*'''Thirst, nocturia, polyuria''' (milder than Bartter)
*'''Constipation'''
*'''Low or normal blood pressure''' — despite elevated renin/aldosterone
*'''Chondrocalcinosis''' — calcium pyrophosphate crystal deposition in joints (from chronic hypomagnesemia); may present with acute '''pseudogout-like''' joint pain and swelling<ref name="KDIGO"/>
*'''Prolonged QT interval''' — present in ~50%; risk of ventricular arrhythmias
*'''Severe presentations''' (uncommon): hypokalemic paralysis (especially in Asian populations), rhabdomyolysis, seizures, ventricular arrhythmia/cardiac arrest

==Differential Diagnosis==
*'''[[Bartter syndrome]]:''' the key differential — more severe, earlier onset, '''hypercalciuria''' (vs hypocalciuria in Gitelman), mimics loop diuretic (vs thiazide); see comparison table on [[Bartter syndrome]] page
*'''Surreptitious vomiting / bulimia:''' urine chloride '''<25 mEq/L''' (Gitelman: '''urine Cl >35 mEq/L''')
*'''Thiazide diuretic use/abuse:''' identical lab picture — '''screen urine for diuretics'''
*'''Laxative abuse:''' low urine potassium (renal potassium wasting distinguishes Gitelman)
*'''Primary hyperaldosteronism:''' '''hypertension present''' (Gitelman is normotensive/hypotensive)
*'''Renal tubular acidosis:''' metabolic '''acidosis''' (not alkalosis)
*'''Hypomagnesemia from other causes:''' PPI use, alcoholism, aminoglycosides, cisplatin — check medication history
*'''Pseudogout (if presenting with chondrocalcinosis):''' check electrolytes in any young patient with calcium pyrophosphate arthropathy — may unmask Gitelman

==Evaluation==
===Workup===
*'''BMP:''' '''hypokalemia''' (often 2.5-3.0 mEq/L), '''hypochloremia''', elevated bicarbonate (metabolic alkalosis)
*'''Magnesium:''' '''low''' (<1.6 mg/dL) in most patients — '''always check magnesium when you find hypokalemia'''
*'''Urine electrolytes:'''
**'''Urine chloride >35 mEq/L''' — confirms renal salt wasting (excludes vomiting)
**Urine potassium elevated (inappropriate renal K wasting)
**'''Urine calcium:creatinine ratio LOW''' (hypocalciuria) — '''the key distinction from Bartter''' (which has hypercalciuria)
*'''ECG:''' prolonged QT, flattened T waves, U waves, ST depression; assess for arrhythmia
*'''Urine drug screen for diuretics''' — must exclude thiazide abuse before diagnosing Gitelman

===Diagnosis===
*'''Hypokalemic hypochloremic metabolic alkalosis + hypomagnesemia + hypocalciuria + normal/low BP + urine Cl >35''' = Gitelman pattern
*Exclude vomiting (urine Cl <25), diuretic abuse (urine drug screen), and medications causing hypomagnesemia
*Genetic testing (SLC12A3 mutations) is confirmatory but not an ED test
*'''Clinical and biochemical diagnosis is sufficient''' to initiate treatment

==Management==
*'''Correct hypokalemia:'''
**'''IV KCl''' for severe hypokalemia (<2.5 mEq/L), ECG changes, or arrhythmias
**Oral KCl for mild-moderate cases
**'''Correct hypomagnesemia FIRST''' — magnesium deficiency causes '''refractory hypokalemia''' that will not correct until magnesium is repleted<ref name="StatPearls"/>
*'''Correct hypomagnesemia:'''
**'''IV magnesium sulfate''' (2 g over 15-30 min, then infusion) for severe hypomagnesemia, tetany, or arrhythmias
**Oral magnesium supplementation for chronic management (magnesium oxide, magnesium citrate)
**GI side effects (diarrhea) limit oral magnesium dosing — a major compliance issue
*'''Cardiac monitoring:''' continuous telemetry if K <3.0 mEq/L, prolonged QT, or any arrhythmia
*'''Continue home medications:''' potassium-sparing diuretics (amiloride, spironolactone), oral potassium and magnesium supplements — '''do NOT discontinue'''
*'''Do NOT use thiazide diuretics''' — this worsens the underlying defect
*'''NSAIDs (indomethacin):''' sometimes used chronically as adjunctive therapy (reduces prostaglandin-mediated salt wasting) — continue if prescribed
*'''Treat precipitating illness:''' any condition causing vomiting, diarrhea, or fever can precipitate electrolyte crisis in Gitelman patients

==Disposition==
*'''Admit:'''
**Severe hypokalemia (<2.5 mEq/L) or symptomatic hypokalemia (arrhythmia, paralysis, rhabdomyolysis)
**Tetany or seizures
**QT prolongation with arrhythmia
**Unable to tolerate oral supplements
*'''Discharge with close follow-up:'''
**Mild-moderate hypokalemia correctable with oral supplements
**No cardiac symptoms or ECG abnormalities
**Tolerating PO
**Nephrology follow-up within 1-2 weeks
*'''New diagnosis suspected''' (unexplained hypokalemic alkalosis + hypomagnesemia + hypocalciuria in a normotensive patient): arrange '''nephrology referral''' for confirmation and long-term management
*'''Counsel patients:''' liberal salt intake; high-potassium foods; take magnesium and potassium supplements reliably; seek care promptly during illness (vomiting/diarrhea can precipitate dangerous electrolyte drops); report palpitations, weakness, or muscle spasms immediately

==See Also==
*[[Bartter syndrome]]
*[[Hypokalemia]]
*[[Hypomagnesemia]]
*[[Metabolic alkalosis]]
*[[Pseudogout]]

==External Links==
*[https://www.ncbi.nlm.nih.gov/books/NBK459304/ StatPearls — Gitelman Syndrome]
*[https://www.kidney-international.org/article/S0085-2538(16)30602-0/fulltext Kidney Int — KDIGO Controversies Conference: Gitelman syndrome (2017)]
*[https://pmc.ncbi.nlm.nih.gov/articles/PMC2518128/ Orphanet J Rare Dis — Gitelman syndrome (2008)]

==References==
<references/>

[[Category:Renal]]

Gitelman syndrome - Revision history

Danbot: Added DDX template transclusions: Hypokalemia, Hypomagnesemia, Metabolic alkalosis, Renal tubular disorders, Prolonged QT

Danbot: Moved intro paragraph into Background section as bullets; removed excessive bold formatting from bullet lead-in text throughout