Hypercalcemia is not a feature of the OPTs unless following restoration of OC action by marrow cell transplantation.(38, 39) In our initial patient harboring SLC29A3 mutations,(4, 5) serum ionized calcium was high‐normal at approximately 1 year old, but decreased after excessive dietary calcium was corrected.(4) In DSS, low serum PTH levels can occur,(9, 10) suggesting mineral homeostasis is impacted. This evidence concerns the gene SLC29A3 and Hypercalcemia.