Hyperparathyroidism complicating CYP 24A1 mutations

CYP24A1 gene mutations induce infantile hypercalcemia, with high 1,25(OH)2D contrasting with low PTH levels. The adult phenotype is not well known. Two unrelated adult patients were referred for nephrolithiasis, hypertension, hypercalcemia, hypercalciuria, normal 25-OHD levels, and inappropriate PTH levels (22 to 92 pg/mL; N: 15–68) suggesting primary hyperparathyroidism, leading to surgery. Hypercalciuria improved despite persistent … Leggi tutto

Therapy‑Resistant Hypercalcemia in a Patient with Inactivating CYP24A1 Mutation and Recurrent Nephrolithiasis: Beware of Concomitant Hyperparathyroidism

We describe a case harboring a homozygous CYP24A1 mutation with mild loss of function, frst presenting with recurrent nephrolithiasis from the age of 22 onward, initially associated with hypercalcemia and low PTH concentrations. Over the years, hyperparathyroidism developed, resulting in more severe hypercalcemia. Also, kidney function deteriorated, most probably as a consequence of biopsy-proven nephrocalcinosis. … Leggi tutto

Autosomal-Recessive Mutations in SLC34A1 Encoding Sodium-Phosphate Cotransporter 2A Cause Idiopathic Infantile Hypercalcemia

Idiopathic infantile hypercalcemia (IIH) is characterized by severe hypercalcemia with failure to thrive, vomiting, dehydration, and nephrocalcinosis. Recently, mutations in the vitamin D catabolizing enzyme 25-hydroxyvitamin D3-24-hydroxylase (CYP24A1)weredescribed that lead to increased sensitivity to vitaminD due to accumulation of the active metabolite 1,25-(OH)2D3. In a subgroup of patients who presented in early infancy with renal … Leggi tutto