ObjectiveGordon's syndrome comprises hypertension, hyperchloremic acidemia, hyperkalemia and intact renal function. We hypothesize that disturbances of one or more cell membrane ion carriers, handling sodium, chloride and potassium, might be relevant in this disorder and, furthermore, that such disturbances might be related to altered cell membrane composition.Design and methods:In a patient diagnosed with Gordon's syndrome, we assessed the kinetics (Kmand maximal rate) of four membrane sodium transport systems in sodium-enriched erythrocytes, according to the technique of Garay. We also measured the lipid composition of erythrocyte membrane in this patient and 69 essential hypertensive controls, using the Iatroscan technique.Results:Compared to reference values of patients with essential hypertension, this patient exhibited a marked increase in the maximal rate of the Na+−K+−2Cl−cotransport (964.0 μmol/l per cell versus the 391.6 + 222 μmol/l per cell in essential hypertensives). Also, there was an increased concentration of erythrocyte membrane phospatidylethanolamine and a reduced concentration of sphingomyelin (27.9 and 11.1% versus 17.9 ± 3.8% and 18.2 ± 3.4%, respectively).Conclusions:We conclude that this abnormality in membrane Na+−K+−2Cl−cotransport could be responsible for the hyperkalemia, hyperchloremic acidemia and increased reabsorption of sodium observed in this condition and, furthermore, that such disturbance in membrane cotransport might be related to altered phospholipid concentration in cell membranes.