CYP24A1 and Hypercalcemia: In our previous publication7, we described a case of biallelic CYP24A1 mutation in a patient presenting with hypercalcaemia, elevated serum 1,25(OH)2D concentration (293 pmol/L, reference range 43–144 pmol/L), and elevated 25(OH)D:24,25(OH)2D VMR of 32.