A Case of Vitamin D-Dependent Rickets, Type 1 / 소아과

"Rickets" is the term applied to impaired mineralization at epiphyseal growth plate, resulting in deformity and impaired linear growth of long bones. Rickets may arise as a result of vitamin D deficiency or abnormality in metabolism. Vitamin D-dependent rickets (VDDR) is rare autosomal recessive disorder in which affected individuals have clinical features of vitamin D deficiency. In 1961, Prader first described this disorder including severe clinical features of rickets, such as hypophosphatemia, hypocalcemia, muscle weakness and seizure. Two distinctive hereditary defects, type I VDDR and type II VDDR have been recognized in vitamin D metabolism. Type I VDDR may be due to congenital defects of renal 1 alpha-hydroxylase, the enzyme responsible for conversion of 25 (OH) D3. These patients have low to detectable 1,25(OH)2D3 in presence of normal to raised 25 (OH) D3. In type II VDDR, renal production of 1,25(OH)2D3 is intact but 1,25(OH)2D3 is not used effectively and target organ resistant to 1,25(OH)2D3 is respectively derived from the abnormality in the vitamin D receptor. We report a case of a 25 month-old girl with typical clinical features of VDDR type I rickets, hypocalcemia, increased alkaline phosphatase and secondary hyperparathyroidism.

Effect of diabetic neuropathy on renal 1-? hydroxylase and bone mineral density in old type 2 diabetic rats / 第三军医大学学报

Objective To investigate the change of renal 1-alpha hydroxylase and its effect on bone mineral density in the old rats with type 2 diabetic nephropathy. Methods Forty Wistar rats of 18 months old were randomly divided into normal control (N), diabetes (D), diabetes treated with vitamin D_ 3 (T1) and diabetes treated with 1-?(OH)D_ 3 (T2) groups, respectively. Ten rats in each group. Dual energy X-ray absorption (DEXA) was used to determine bone mineral density (BMD) of lumbar spines and femoral bone. 24 h urinary protein excretion, serum 25(OH)D_ 3 and 1,25(OH)_ 2 D_ 3 were measured by radioimmunoassay. Results Compared with controls, 24 h urinary protein excretion increased remarkably D, T1, T2 groups, while BMD greatly decreased, much lower in D group and T1 group than T2 group (P0.05). The level of 1,25(OH)_ 2 D_ 3 in N group was the same to T2 group, but higher than D, T1 groups (P