Calcitonin secretion in streak gonad syndrome (Turner's syndrome)

Osteoporosis in one of the most common complications of streak gonad syndrome (SGS), however, its pathogenesis is still unclear. To test whether SGS is associated with calcitonin (CT) deficiency, 11 affected individuals and 8 age-matched healthy women were studied. Calcium, 3.6 mg/kg b.w. as a 10% solution of calcium chloride, was given intravenously for 3 minutes. Serum levels of CT and calcium were measured before and at 5, 30, 60, and 120 minutes after the injection. There was a statistically significant rise in serum calcium levels both in the control subjects and patients with SGS, with significantly lower levels prior to and at 30, 60, and 120 minutes following calcium load in the control group. The CT rise following calcium load was also significant at 5, 30, and 60 minutes in the controls and at 5 and 30 minutes in patients with SGS, with a significantly lower baseline and 30, 60, and 120 minutes levels in the latter group. Maximum levels of calcium and CT occurred 5 minutes after the calcium load and were statistically indistinguishable. There were no significant differences in either the calcium or the CT incremental changes between the two groups. These findings are consistent with decreased basal (and 30-120 minute) CT levels in SGS and suggest that CT deficiency may be involved in the development of osteoporosis in patients with SGS. The possible causal relationship of estrogen deficiency to the reduced CT levels in SGS is discussed.