A variant of nephrogenic diabetes insipidus: V2 receptor abnormality restricted to the kidney

In congenital nephrogenic diabetes insipidus (NDI) blunted responses of plasma factor VIII, von Willebrand factor, and plasminogen activator to the synthetic V₂ analogue 1-desamino-8-d-arginine vasopressin (DDAVP) have been reported. In addition, vasodilatory responses to DDAVP appear to be absent in NDI. We describe a boy, who presented shortly after birth with the typical features of NDI, but who showed normal coagulation, fibrinolytic and vasodilatory responses to DDAVP. We conclude that in this patient the defect is confined to the kidney, while in other NDI patients there may be a general V₂ receptor abnormality. These findings point to heterogeneity in NDI.