We obtained, for the first time, results showing the benefit of treating cryptorchidism during the first year of life rather than in the second year or even later.

In children with syndromic hypoparathyroidism, substitutive treatment with rhPTH (1-34) maintains adequate blood calcium levels and allows prompt normalization of urinary calcium excretion, through direct action on the kidney and through calcium and vitamin D therapy layoff.

Hyponatremia is the most common electrolyte disorder among hospitalized patients and it is sometimes considered as a poor outcome predictor. Its correction is thus indicated, even in asymptomatic patients. The conventional treatment consists of fluid restriction in presence of euvolemia or hypervolemia; loop diuretics are used in some hypervolemic conditions such as cardiac heart failure, liver cirrhosis and nephrotic syndrome, while intravenous isotonic or hypertonic solutions are administered in hypovolemic conditions. The utilization of demeclocycline and urea is not indicated in pediatric ages due to lack of data on their toxicity and poor tolerance. Recently, a new therapeutic option has been developed, a class of non-peptide arginine vasopressin receptor antagonists called vaptans. Tolvaptan is the only such agent approved in Europe for the treatment of hyponatremia caused by syndrome of inappropriate antidiuretic hormone secretion (SIADH) in adults. In USA, tolvaptan and conivaptan have been approved for treatment of euvolemic and hypervolemic hyponatremia. Few data are so far available in paediatric patients, since only one trial has been registered in Europe which includes children and adolescents, but this trial is still ongoing. Here, we report three children with chronic hyponatremia due to SIADH in which tolvaptan has been used successfully.

Copeptin evaluation holds promises as a diagnostic tool in paediatric PPS; its interpretation might be useful to promptly distinguish NDI, even avoiding the WDT need.