Chronic Hyperkalemia, Metabolic Acidosis and Short Stature in Two Siblings-the Spitzer-Weinstein Syndrome

Abstract

Patients with NS have several disorders of calcium metabolism: hypocalcemia, hypocalciuria and probably decreased intestinal absorption of calcium. In order to evaluate the mechanisms responsible we have studied in 23 children, 3-12 years old, with NS and normal rend1 function, total and ionized calcium, calciuria, and blood levels of 25-hydroxyvitamin D and of Cc-protein.The studies were performed when proteinuria was>200 mglhlmq and repeated during remission of NS. The blood levels of 25HCC and of Gc-protein were significantly lower than that in normdl subjects (p<0.01) and there wds d direct correlation between albuminemia and pldsma levels of 25HCC, and an inverse correlation between the degree of proteinuria and 25 HCC. The loss of metabolites of vitamin D circulating bound to Gcproteins seems the main cause of the disorders in calcium metabolism observed in NS. parameter can be estimated from the data of intake, NAE can be predicted. In steady state conditions the urinary excretion of electrolytes correlates with their intestinal absorption, which can be estimated from intake and absorption rate. Absorption from the gut was estimated in the following way: Na + Cl: 100%; K: 90%; Ca: 0.17 x Ca intake (mg) + 60; Mg: 0.39 x Mg intdke (mg) -23; P: 0.642 x P intake (mg) -11. 75% of the ingested organic sulfur (methionine and cystine) is oxidized to SO dnd excreted in the urine. 03 excretion is almost independent ?rum the diet (38 meq/d/1.73m ). The usefulness of this theoretical model to estimate NAE was demonstrated in acid-base studies of children with phenylketonuria receiving two synthetic amino acid mixtures (PAM with a high NAE of 4-6 meq/kg/d, PAM74with a low NAE of 1 meq/kg/d).FAMILIAL HYPOKALAEMIA AND HYPOMAGNESAEMIA. GITELMAN'S SYNDROME. REPORT OF 6 CASES. McCredie, D.A., Powell, 3 H.R., and Rotenberg, E., Dept. of Paediatrics, University of Melbourne, Austrdlid.Six cases of renal wdsting of potassium and mdgnesium are described in four families. Four patients presented with tetany, whilst two were asymptomatic siblings of these. One patient also suffered from a progressive external ophthalmoplegia syndrome and mental retardation, whilst the remaining five were normal in physical and intellectual development. One patient (now aged 31 yrnrs) hns subsequently giver^ birth t o two r~urrn.al clllldrt,rx, but maintains very low serum levels of both potassium (2.0 mM) and magnesium (0.5 mM) when off electrolyte therapy. No abnormalities in calcium metabolism were found and there was no other evidence of tubular reabsorptive defect apart from slight defects in urinary concentration and acidification. In particular sodium chloride conservation appeared normal. Plasma renin levels were normal, or slightly raised in these patients and urinary aldosterone levels were normal, distinguishing this condition from Bartter's syndrome. Magnesium loading did not affect potassium wasting, nor did potassium loading alter the renal handling of magnesium. Spironolactone was able to improve tubular reabsorption of potassium, ...