[Changes in bone metabolism in girls with Turner's syndrome]

Data of the prevalence of osteoporosis in girls with Turner's syndrome are not uniform, and its causes have not been fully elucidated. Information on the mineralization of osseous tissue is controversial. The objective of the present work was to examine some more recent indicators of bone metabolism in a group of girls with Turner's syndrome.

A group of girls aged 4-20 years was examined where genetic examination had revealed karyotype 45 X (7 patients) or mosaic 45 X (46 XX) (9 patients). On X-ray examination osteoporosis was found in 71%, densitometric evidence of reduced bone density was provided in 2% of the examined patients. As to biochemical osteologically oriented examinations, a significantly reduced osteocalcin value was found (1.18 +/- 0.42 mug/l, as compared with 11.38 +/- 0.03 in controls, p < 0.001), reduced values of alkaline phosphatase (2.67 mukat/l as compared with 8.46 +/- 4.16 mukat/l in controls, p < 0.005) and reduced values of the bone isoenzyme of alkaline phosphatase (1.47 mukat/l as compared with 6.04 +/- 0.27 in controls, p < 0.001). The values of calcemia (2.63 / 0.13 mmol/l) and phosphataemia (1.36 +/- 0.25 mmol/l) did not differ significantly from values recorded in controls. To six patients the authors administered for a period of three months 1,25(OH)2D3, 0.25 mg on alternate days. The osteocalcin values rose to 5.27 +/- 3.14 micrograms/l, similarly as alkaline phosphatase (6.32 +/- 1.83 mukat/l) and the bone isoenzyme of alkaline phosphatase (2.42 +/- 1.95 mukat/l), not evaluated statistically because of the small number of patients.

In girl with Turner's syndrome a reduced bone density was revealed in 25%, reduced values of osteocalcin, alkaline phosphatase and its bone isoenzyme indicate a reduced osteoblast activity. It appears that administration of 1,25(OH)2D3 can have a favourable effect.