Clinical Phenotype in a Toddler with a Novel Heterozygous Mutation of the Vitamin D Receptor

Table 1

Metabolic parameters on diagnosis and during RX.

Time after diagnosis (weeks)	Calcium; (mg/dl)	Alkaline phosphatase; (IU/L)	25-OH vitamin D2; (ng/ml)	1,25(OH) vitamin D3; (pg/ml)	PTH; (pg/ml)	Calcium/creatinine ratio (urine)
Baseline	7.6	2023	14	505	1115	0.15
2 weeks	7.3	1579	31	901	764	0.06
1 month	7.8	1708	20	784	924	0.31
1.5 months	7.7	1879	44	1165	866	0.29
2 months	7.9	1579	36	901	901	ND
3 months	7.9	1686	40	959	959	0.12
4 months	8.8	1343	44	2064	437	0.17
5 months	8.2	848	41	1300	536	0.3
8 months	8.7	705	33	>600	300	ND
10 months	9.5	662	36	>600	147	ND
12 months	9.5	441	58	>600	210	ND
16 months	9.4	287	45	>600	76	0.06
21 months	9.7	180	43	>600	35	0.06

Metabolic parameters (reference values): calcium = 8–10.4 mg/dl; alkaline phosphatase = 25–100 IU/L (adult reference in our lab, with 80% bone isoenzyme); PTH = 14–72 pg/ml; 25-OH vitamin D2 = 30–100 ng/ml; 1,25(OH) vitamin D3 = 19–79 pg/ml. ND: not done.