Nephrocalcinosis is seen -

Medullary sponge kidney is one of several common causes of medullary nephrocalcinosis. Medullary nephrocalcinosis is defined as the deposition of calcium salts in the medulla of the kidney Nephrocalcinosis is a disorder that occurs when too much calcium is deposited in the kidneys. It commonly occurs in premature infants. Individuals may not have symptoms or may have symptoms related to the condition causing nephrocalcinosis. Later symptoms may be associated with chronic kidney failure. Ref Harrison20th edition pg 267