PTH and Hypercalcemia: Finally, mutations of the CYP24A1 gene with autosomal recessive transmission may induce a biological phenotype, characterized by hypercalcemia, hypercalciuria, depressed PTH, normal 25-OHD, increased 1-25-(OH)2D, and decreased 24-25-(OH)2D3 levels, characteristic of infantile hypercalcemia, which may also be related to SLC34A1 gene mutations.