Síndrome de Gitelman: confusión diagnóstica en una paciente con antecedentes de Trastorno de la conducta alimentaria / Gitelman's Syndrome: diagnosis in a female patient with a history of eating disorders

Introducción. El síndrome de Gitelman es una tubulopatía distal, generalmente de herencia autosómica recesiva, que cursa como una alcalosis metabólica con hipomagnesemia e hipocalciuria. Mientras que la causa de la hipomagnesemia se desconoce, la hipocalciuria se explica por la disminución de la entrada de cloruro de sodio en el túbulo distal. Estos pacientes pueden presentar debilidad muscular, fatiga, hipotensión y condrocalcinosis secundaria a la hipomagnesemia crónica. Su tratamiento consiste en potasio, magnesio oral y diuréticos ahorradores de potasio. El diagnóstico puede retrasarse durante años, ya que los pacientes pueden mantenerse asintomáticos durante largos períodos de tiempo. Las alteraciones bioquímicas con las que cursa pueden orientar hacia otros diagnósticos. Métodos. Se describe el caso de una mujer afecta de este síndrome. Resultados. El diagnóstico clínico se confirmó por el estudio de las mutaciones del gen SLC12A3. Conclusiones. pesar de los antecedentes psicopatológicos de los pacientes, es preciso y necesario descartar siempre una enfermedad orgánica, que puede confundir el diagnóstico al tener en común las mismas alteraciones clínicas, bioquímicas y del medio interno (AU)

Gitelman Syndrome is a pathology in the distal tubule, generally of autosomal recessive inheritance, presenting as a metabolic alkalosis with hypomagnesemia and hypocalciuria. While the cause of hypomagnesemia is unknown, hypocalciuria is explained by the reduction of sodium chloride entrance in the distal tubule. Patients suffering from Gitelman Syndrome may present muscular weakness, fatigue, hypotension and chondrocalcinosis secondary to chronic hypomagnesemia. The treatment consists on potassium, oral magnesium and potasium-sparing diuretics. Diagnosis may be delayed for years, given that patients can remain asymptomatic for long periods of time. Biochemical alterations can lead to other diagnosis (AU)

Bartter syndrome presenting as poor weight gain and abdominal mass in an infant.

Bartter syndrome, a group of disorders that encompasses multiple genetic defects with similar clinical presentation, has been divided into six different genotypes, according to different genetic defects, and into three main clinical variants (or phenotypes). Classic laboratory findings in all variants include hypochloremia, hypokalemia, and metabolic alkalosis with excessive excretion of chloride and potassium. Classic Bartter syndrome, neonatal Bartter syndrome, and Gitelman syndrome are the three main clinical variants. Classic Bartter syndrome and neonatal Bartter syndrome have defects in genes that affect transport channels in the ascending loop of Henle, where as in Gitleman syndrome the defect occurs in the transport channels of the distal convoluted tubule. Classic Bartter syndrome and neonatal Bartter syndrome have similar presenting symptoms, potential outcomes, and treatment, but different ages at presentation. Gitelman syndrome, a more benign condition than the other clinical variants, has the classic hallmark finding of hypomagnesemia and low to normal excretion of calcium. This differentiates it from the classic and neonatal variants of the disease. With early diagnosis and proper treatment, Bartter syndrome has a good prognosis. But failure to identify it can lead to tubulointerstitial nephritis and renal failure. We present a case of a 6-month-old boy with Bartter syndrome who presented with poor weight gain and an abdominal mass.

Metabolic effects of chloride-deficient formula.

A seven-month-old infant presented with failure to thrive and hypochloremic alkalosis due to intake of chloride-deficiency formula. The metabolic changes were associated with hyperreninemia and hyperaldosteronism. Within one month of supplementation with a formula adequate in chloride content, the patient started to gain weight. Five months after adequate chloride intake, all metabolic parameters including plasma renin and plasma aldosterone were normal.

The dietary chloride deficiency syndrome.

Chronic depletion of body chloride developed in a group of infants ingesting a diet consisting almost exclusively of chloride deficient Neo-Mull-Soy. Ten of the 12 infants were on this diet three to five months before loss of appetite, failure to thrive, muscle weakness, and lethargy led to a diagnostic evaluation. The outstanding laboratory features were severe hypokalemic metabolic alkalosis, low urinary chloride concentrations (< 10 mEq/liter), and erythrocyturia. There was marked decrease in weight for age in all 12 infants. Head circumference for age had decreased in five of six and length for age in five of ten infants for whom earlier measurements were available. The biochemical abnormalities reverted to normal following dietary supplementation with either sodium or potassium chloride. Appetite, affect, and muscle strength improved, and weight gain resumed. Head circumference for age has moved toward the percentile level present prior to starting Neo-Mull-Soy in all instances. With one exception, length measurements show a similar pattern. The erythrocyturia has decreased or vanished. Chloride deficiency led to contraction of the extracellular volume and the substitution of poorly reabsorbable anions for readily reabsorbable chloride. These alterations caused development of the negative hydrogen ion and potassium balances which led to the hypokalemic metabolic alkalosis.