A case report of Gitelman syndrome resulting from two novel mutations in SLC12A3 gene

Hypokalaemia is a common clinical problem. A potential but commonly overlooked cause of hypokalaemia is Gitelman syndrome. A 26-year-old man was admitted to the hospital due to syncope with general and muscular weakness and muscle cramps. The patient's history revealed previous recurrent syncope events associated to hypokalaemia with the lowest serum potassium value being 2.6mmol/l. At admission, blood pressure was normal and no changes were found at physical examination. Laboratory tests showed mild hypokalaemia (3.0mmol/l), hypomagnesaemia (1.36mg/dl), hypocalciuria (< 40mg/24h), and metabolic alkalosis (HCO3− 29.7mmol/l, BE 5.3mmol/l). Further laboratory tests (FeK, TTKG) confirmed inappropriate kaliuresis. Conn's disease was excluded by hormonal and imaging assessments. Genetic testing was performed and two novel heterozygous mutations: c.35_36insA and c.1095+5G>A were found in transcript NM_000339.2 in SLC12A3 gene. The patient was diagnosed with Gitelman syndrome and was treated with supplements of potassium and magnesium. La hipopotasemia es un problema clínico común. El síndrome de Gitelman es una posible causa de hipopotasemia a veces no reconocida. Un hombre de 26 años de edad ingresa en un hospital por causa de un síncope, debilidad generalizada y calambres musculares. La historia clínica del paciente reveló la incidencia del síncope con hipopotasemia recurrente con el valor más bajo de potasio en 2,6mmol/l. En el ingreso, el paciente presentaba una presión arterial normal y la exploración física no reveló ninguna enfermedad. La evaluación del laboratorio demostró una hipopotasemia leve (K+ 3,0mmol/l), hipomagnesemia (Mg 1,36mg/dl), hipocalciuria (A fueron encontradas en la transcripción NM_000339.2 del gen SLC12A3. El paciente fue diagnosticado con el síndrome de Gitelman y fue tratado con suplementos de potasio y magnesio.