A case of juvenile essential hypertension: implications of erythrocyte net Na+, K+ flux measurement.

In recent studies were reported an inherited membrane defect which is closely related to the development of essential hypertension. This abnormality consists of a functional deficiency in the Na+--K+ co-transport mechanism in erythrocytes of essential hypertensives and some normotensives born of hypertensive parents. Here we report a case of juvenile essential hypertension including familial erythrocyte Na+, K+ measurements. The 2-year-old boy had essential hypertension and bore the abnormality, with no compensatory activity of the Na+, K+ pump. The mother had developed hypertension during pregnancy. She also bore the erythrocyte abnormality as the net Na+/K+ flux ratio was reduced. One sister bore the same abnormality without hypertension but a complete analysis of Na+ extrusion mechanisms in this patient demonstrated a compensatory effect of the Na+, K+ pump activity. Other members of the family were normotensive without the flux abnormality. It appears therefore that erythrocyte flux measurements might be of diagnostic and genetic interest in juvenile hypertension.