1/5. rickets in an infant with williams syndrome.calcium homeostasis is altered in patients with williams syndrome. We report an infant in whom williams syndrome was diagnosed at 4 weeks who presented with hypercalcemia, hypercalciuria, and medullary nephrocalcinosis. fluorescence in situ hybridization demonstrated a deletion of the elastin gene on chromosome 7. This infant was treated with a low-calcium/vitamin d-deficient infant formula that resulted in the development of rickets. Replacement of the low-calcium/vitamin d-deficient formula with standard formula led to resolution of the rickets.- - - - - - - - - - ranking = 1keywords = nephrocalcinosis (Clic here for more details about this article) |
2/5. Severe hypophosphatasia due to mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene.hypophosphatasia is a rare autosomal recessive inborn error of metabolism characterized by a defective bone mineralisation and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase activity. We report the characterisation of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutation in a patient affected by infantile hypophosphatasia. This boy was the first child of non affected, non related parents. At 1 month of age he presented with palsy of the left upper limb with hypotonia. Length was - 2SD. The anterior fontanel was large. There was a markedly decreased ossification of all bones. All limbs were shortened. Ultrasonographic examination of the kidneys showed nephrocalcinosis. Level of alkaline phosphatases was decreased in the child as well as in the parents. bone density was decreased. At 2 years of age development was delayed. Weight was - 3,5 SD and OFC - 3SD. The child had craniosynostosis. Molecular studies showed 2 missense mutations, both in exon 6 of the TNSALP gene.- - - - - - - - - - ranking = 1keywords = nephrocalcinosis (Clic here for more details about this article) |
3/5. A girl with rickets and nephrocalcinosis.A 5-year-old girl presented with short stature. She was found to have rickets due to renal phosphate wasting and nephrocalcinosis. serum parathyroid hormone was suppressed, 25-OH vitamin d was within the normal range, and 1,25-(OH)(2 )vitamin d was elevated. In addition, she had hypercalciuria, proteinuria, which was partially tubular in origin, and a reduced glomerular filtration rate of 58 ml/min per 1.73 m(2). Treatment with phosphate supplements resulted in healing of the rickets and normalization of the serum 1,25-(OH)(2 )vitamin d level. This patient is an example of hypercalciuric rickets, most likely due to an inherited disorder of phosphate metabolism. Hypercalciuric rickets can be inherited as an autosomal recessive as well as autosomal dominant trait.- - - - - - - - - - ranking = 5keywords = nephrocalcinosis (Clic here for more details about this article) |
4/5. Oral alendronate therapy for severe vitamin d intoxication of the infant with nephrocalcinosis.vitamin d intoxication is a well-known cause of hypercalcemia in children. We report here the use of oral alendronate for the treatment of hypercalcemia due to vitamin d intoxication in a 7 month-old infant with nephrocalcinosis. The serum calcium levels were normalized without complications. Oral alendronate therapy may be safely used in hypercalcemia due to vitamin. D intoxication in pediatric patients with nephrocalcinosis resistant to hydration, diuretics or corticosteroids.- - - - - - - - - - ranking = 6keywords = nephrocalcinosis (Clic here for more details about this article) |
5/5. hyperparathyroidism in patients with X-linked dominant hypophosphatemic rickets--application of the calcium infusion test as an indicator for parathyroidectomy.Two children with X-linked dominant hypophosphatemic rickets treated with vitamin-D metabolites and phosphate supplementation, for prolonged periods, developed hyperparathyroidism with nephrocalcinosis. calcium infusion tests were performed in both. In one patient, the initial test was done two weeks after all treatment was stopped. Only moderate decrease in the degree of the phosphaturia was recorded. However, a repeat test, performed after all medications were withheld for another four weeks, showed normal anti-phosphaturic response, and she continued to be treated conservatively. In the other patient, the test was done five weeks after withholding treatment. Failure to suppress the phosphaturia provided strong support for the diagnosis of tertiary hyperparathyroidism. He underwent total parathyroidectomy and the parathyroid histology confirmed the diagnosis. In both, control of parathyroid activity stopped the deterioration in kidney function and improved the response of the basic disorder to treatment. It is concluded that in patients with X-linked dominant hypophosphatemic rickets, the calcium infusion test is useful for the differentiation between secondary-reversible and tertiary-irreversible hyperparathyroidism. To avoid continued stimulation of the parathyroid glands by phosphate administration, we recommend that such calcium infusion test be performed and interpreted after at least six weeks have elapsed without phosphate or vitamin-D administration.- - - - - - - - - - ranking = 1keywords = nephrocalcinosis (Clic here for more details about this article) |