title: Leaky cell syndrome: a rare cause of pseudohyperkalaemia.
abstract: Life-threatening situations of hyperkalaemia are often caused by renal failure, hyperglycaemia or medication. However pseudohyperkalaemia, a falsely elevated potassium concentration, is usually caused by haemolysis, repeated clenching of the fist during venepuncture or abnormal cell numbers. Another rare cause of pseudohyperkalaemia is familial pseudohyperkalaemia, an autosomal dominantly inherited trait, with increased leakage of potassium from erythrocytes. Under normal in vivo conditions, this increased leakage is compensated by augmented activity of the Na(+)/K(+) ATPase pump. However, after venepuncture the blood cools down to room temperature, reducing the activity of the Na(+)/K(+) ATPase pump whereby the increased potassium leakage becomes more apparent. Here, we present a Dutch patient with extreme familial pseudohyperkalaemia. Interestingly, his two children also show increased potassium leakage at room temperature, albeit at a lower level. Despite the low prevalence of familial pseudohyperkalaemia, it can have important clinical implications and rapid recognition is desired.
authors: Department of Clinical Chemistry, Medisch Spectrum Twente Hospital Group, PO Box 50000, Enschede 7500 KA, The Netherlands. m.lukens@mst.nl
authors: Michaël V
authors: MV
authors: Lukens
authors: Arjan
authors: A
authors: de Mare
authors: Marjo J
authors: MJ
authors: Kerbert-Dreteler
authors: Frank A
authors: FA
authors: van den Bergh
mesh_terms: D000368:Aged; D002648:Child; D005260:Female; D005799:Genes, Dominant; D006461:Hemolysis; D006801:Humans; D006947:Hyperkalemia / Q000097:blood* / Q000235:genetics; D008297:Male; D010375:Pedigree; D018962:Phlebotomy; D011188:Potassium / Q000097:blood*; D019655:Quantitative Trait, Heritable; D012964:Sodium / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism
chemical_list: D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium