My daughter has had high calcium levels since birth she is now a year old and nothing has changed. what can cause this?

Familial?: There are many possible causes for high calcium levels, though they typically occur in adults rather than children. There is a disorder called "familial hypocalcuric hypercalcemia), in which various family members have a mild defect in eliminating calcium through the kidneys. Blood calcium levels are high, PTH levels are typically high normal. One of the parents should have the same problem.