Calcium metabolism in Williams-Beuren syndrome.
J Pediatr
; 121(6): 902-7, 1992 Dec.
Article
em En
| MEDLINE
| ID: mdl-1333009
Increased 1,25-dihydroxyvitamin D levels and decreased basal and calcium-stimulated calcitonin serum levels have been found in children with Williams-Beuren syndrome (WBS). To determine whether isolated or combined disturbances of secretion or action of the calcium-regulating hormones may cause the tendency to hypercalcemia in WBS, we investigated several aspects of calcium metabolism in 27 normocalcemic children and adults, aged 2 to 47 years, with WBS. With the exception of slightly decreased 25-hydroxyvitamin D and slightly increased calcitonin in serum, all measured basal indexes of calcium and bone metabolism, including the serum levels of intact parathyroid hormone and 1,25-dihydroxyvitamin D, were comparable to control values. Total and extractable calcitonin, the latter representing the monomeric and biologically important form of the hormone, showed the same relative increase after a low-dose calcium infusion in patients and control subjects, indicating a normal capacity of the calcitonin-producing C cells of the thyroid gland in WBS. Furthermore, exogenous parathyroid hormone induced a normal response of 1,25-dihydroxyvitamin D, cyclic adenosine monophosphate, and phosphate excretion, indicating a normal response of the renal 25-hydroxyvitamin D-1 alpha-hydroxylase and the renal receptor-adenylate cyclase system to parathyroid hormone. These findings suggest that neither deficient calcitonin secretion nor increased renal sensitivity to parathyroid hormone is a feature of WBS in normocalcemic patients.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estenose da Valva Aórtica
/
Cálcio
/
Expressão Facial
/
Deficiência Intelectual
Limite:
Adolescent
/
Adult
/
Child
/
Child, preschool
/
Humans
/
Middle aged
Idioma:
En
Revista:
J Pediatr
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
Alemanha
País de publicação:
Estados Unidos