Hereditary Hypercalcemia Caused by a Homozygous Pathogenic Variant in the CYP24A1 Gene: A Case Report and Review of the Literature

Table 1

Clinical and biochemical data at admission to our clinic.

Analyte	Result	Normal adult; reference range
Total calcium (mg/dL)	10.5	8.6-10.2
Ionized calcium (mmol/L)	1.35-1.36-1.45	1.13-1.32
Phospate (mg/dL)	3.1	2.7-4.5
Magnesium (mg/dL)	2.02	1.7-2.2
Albumin (g/dL)	4.6	3.6-5.2
PTH (pg/mL)	< 4-7	8-40
Calcitonin (pg/mL)	< 2	< 11.5
25-hydroxy vitamin D (ng/mL) ^§	30.3
1,25-dihydroxyvitamin D (pg/mL)	107	20-67
Osteocalcin (ng/mL)	61.6	6.8-34
Bone-specific alcaline phophatase (mcg/L)	23	2-20
Carboxy-terminal collagen crosslinks (ng/mL)	1.042	0.112-0.738
Urine calcium (mg/24h)	150-410-455	100-321
Urine phosphates (mg/24h)	697-875	400-1300
Urine magnesium (mg/24h)	140-164	60-120
Creatinine (mg/dL)	0.69-0.72	0.5-0.9
Urine creatinine (mg/24h)	1050-1085-1148	740-1570
Angiotensin converting enzyme (U/L)	80	65.8-114.4

When available, repeated measures are reported
§: 25(OH)D was assayed at University of Pisa laboratory as total 25(OH)D (i.e. the sum of 25(OH)D₂ + 25(OH)D₃) using a chemiluminescence immunoassay (IDS-iSYS, Immunodiagnostic systems, Boldon, Tyne and Wear, UK)
∫: 1,25(OH)₂D was assayed at University of Pisa laboratory as total 1,25(OH)₂D (i.e. the sum of 1,25(OH)₂D₂ + 1,25(OH)₂D₃) using a radioimmunoassay (IDS, Immunodiagnostic systems, Boldon, Tyne and Wear, UK)