Distal renal tubular acidosis in primary hyperparathyroidism

Primary hyperparathyroidism manifests biochemically as a disturbance in serum calcium homeostasis. The kidney appears to be the central organ that sets the serum calcium level. Hyperchloraemia, defective urinary acidification and renal tubular acidosis have been reported to be associated with primary hyperparathyroidism. Distal renal tubular acidosis due to primary hyperparathyroidism is rarely reported. Renal tubular dysfunction due to significant hypercalciuria appears to be one of the proposed mechanisms. This case report will highlight a case of primary hyperparathyroidism in a 26-year old Filipino man due to a solitary functioning parathyroid adenoma presenting with recurrent nephrolithiasis leading to distal renal tubular acidosis manifesting with hypokalaemia and hypomagnesaemia. The patient underwent a minimally invasive selective parathyroidectomy that resulted in full reversal of hypercalcaemia and hyperparathyroidism together with the features of distal renal tubular acidosis. He is currently on frequent follow-up for monitoring of electrolyte abnormalities and gradual resolution of nephrocalcinosis.