Calcium-ATPase activity in erythrocyte ghosts from patients with familial benign hypercalcaemia

It has been suggested that the parathyroid glands and the kidneys are insensitive to the high extracellular calcium levels found in familial benign hypercalcaemia (FBH) (familial hypocalciuric hypercalcaemia) and that there may be a general disorder of the plasma membrane 'calcium pump'. We have found that the activity of the calcium-stimulated, magnesium-dependent ATPase of erythrocyte ghost membranes from patients with FBH was significantly higher (p