AUTONOMOUS HYPERPARATHYROIDISM IN X-LINKED HYPOPHASPHATAEMIA

Four patients with familial hypophosphataemic rickets developed signif icant hypercalcaemia which persisted after discontinuation of vitamin D therapy. They had increased PTH levels and were operated for hyperpa rathyroidism at the ages of 18, 20, 24 and 45 years, respectively. Thr ee of the patients had previously received phosphate treatment and one patient developed hyperparathyroidism 7 years after treatment with ca lcitriol. Histological evaluation revealed different degrees of parath yroid hyperplasia in all patients, with persistently increased PTH and /or calcium levels after surgery, The possibility of autonomous hyperp arathyroidism should be evaluated in the follow-up of patients with X- linked hypophosphataemic rickets.