No abstract

The incidence of spontaneous puberty in Turner's syndrome is reported to be between 5-10% and, more recently in some series, as high as 20%. In an Italian retrospective multicenter study, of 522 patients older than 12 yr with Turner's syndrome, 84 patients (16, 1%) presented spontaneous pubertal development with menarche that occurred at a chronological age of 13.2 +/- 1.5 yr (mean +/- SD) and a bone age of 12.9 +/- 1.9 yr. Karyotype distribution in the whole group was as follows: 52.1% (272 patients) X-monosomy (45,X), 13.2% (69 patients) mosaicism characterized by X-monosomy and cellular line with no structural abnormalities of the second X, 19.9% (104 patients) mosaicism characterized by X-monosomy and cellular line with structural abnormalities of the second X, and 14.8% (77 patients) structural abnormalities of the second X. Menstrual cycles were still regular in 30 patients at 9.2 +/- 5.0 yr after menarche, 12 developed secondary amenorrhea 1.6 +/- 2.0 yr after menarche, and 19 had irregular menstrual cycles 0.9 +/- 1.8 yr after menarche. As signs of spontaneous puberty developed in 14.0% of X-monosomic patients and in 32.0% of patients with cell lines with more than one X, the presence of the second X seems to have a cardinal influence on the appearance of spontaneous puberty. Spontaneous pregnancy occurred in 3 patients (3.6%). The presence of chromosomal abnormalities and malformations in 2 of 3 pregnancies led us to agree with other investigators in discouraging unassisted pregnancies. Treatment with GH does not seem to exert any influence on either the age of onset or the prevalence of spontaneous pubertal development in Turner's syndrome. The increased percentage of spontaneous menarche is Turner's syndrome reported in the recent literature might be due to increased ascertainment by diligent screening for Turner's syndrome in girls with short stature and mild or no Turner's syndrome stigmata, even though they may be menstruating.

Final height of 4 patients with Noonan syndrome and short stature treated with growth hormone (GH) is reported. Four prepubertal girls (chronological age 12.3-15.1 years, bone age 11.0-11.5 years) were treated with recombinant human growth hormone (0.5 IU/kg/week s.c.) for at least 3 years. Stimulated GH secretion was normal, spontaneous nocturnal GH secretion was low in 1 patient. Final height, as standard deviation score according to Ranke-specific standards for Noonan syndrome, improved in 3 patients and 2 of them exceeded their corrected midparental height.

Growth hormone (GH), alone or in combination with anabolic steroids, seems to improve the growth rate in Turner syndrome, but to exert a less striking effect on the final height (FH). Reports on the FH usually lack a control group, and the GH effect is determined using the gain in centimeters over projected height. Out of a cohort of 32 Turner syndrome girls under recombinant human GH (rhGH) therapy (0.5 IU/kg/week during the 1st year and 1 IU/kg/week subsequently), 18 (treated for 3-6 years) attained FH. The mean chronological age at the first examination was 9.6 ± (SD) 2.1 years and at the start of GH therapy 13.0 ± 2.0 (range 8.8-17.2) years. Eighteen untreated subjects matched for chronological age and karyotype served as control group. The FH as SDS according to Lyon and to unpublished Italian Turner syndrome girl standards was not significantly different as compared with pretreatment. In comparison with Italian cross-sectional Turner syndrome standards (FH 142.5 ± 7.0 cm), the FH of the control group was quite similar (142.2 ± 4.9 cm), whereas the rhGH-treated group showed a FH of 147.6 ± 7.3 cm with a mean increment of about 5 cm. The height gain during therapy (as delta height in SDS either according to Lyon or to Italian SDS standards) was compared for each girl with that of a matched girl of the control group during a comparable observation period. A significantly different delta height was observed in the treated versus control groups: 0.3 ± 1.1 vs. -1.0 ± 0.8 according to Lyon (p < 0.001) and 0.8 ± 0.7 vs -0.3 ± 0.5 according to Italian standards (p < 0.001). If we compared the FH with the projected height according to Lyon standards, the height gain (as delta height in cm) was significantly higher than in the untreated subjects (-1.1 ± 4.8 vs. -6.2 ± 3.9 cm; p < 0.05). It seems worthwile to undertake GH treatment in Turner syndrome girls who represent a very short statured population, even though the response is less significant than in classic GH deficiency and shows a striking variability, probably due to a sort of peripheral resistance.

The age-related decline in spontaneous growth hormone (GH) secretion has been suggested to cause growth failure in girls with Turner syndrome (TS). We studied 23 girls (mean age ± SD: 11.1 ± 2.7 years) diagnosed to have TS by karyotype analysis. The control group consisted of 18 prepubertal age-matched subjects (10.7 ± 2.5 years) with growth retardation due to familial short stature and/or constitutional growth delay. In addition, 18 children (10.9 ± 3.3 years) diagnosed to have GH deficiency by two different provocative tests were chosen as a further comparison group. Spontaneous 12-hour nocturnal GH secretion was assessed by RIA at 30-min intervals. Plasma insulin-like growth factor 1 (IGF-1) levels were determined by RIA after acid-ethanol extraction. Girls with TS had a percentage of ideal body weight significantly higher than controls (p < 0.0001) and showed spontaneous GH secretion significantly lower than controls (mean ± SD: 3.2 ± 1.6 in TS vs. 5.5 ± 1.3 µg/l in controls; p < 0.0001) but higher than GH-deficient patients (1.3 ± 0.8 µg/l; p < 0.0001). No significant difference was found in IGF-1 levels between TS patients and controls, whereas GH-deficient children showed IGF-1 levels significantly lower than those of TS patients (p < 0.0005). As expected, GH concentrations correlated with bone age in controls (r = 0.51, p < 0.05), whereas no relationship was seen in TS. Interestingly, in TS, GH levels were negatively related to the percentage of ideal body weight (r = -0.43, p < 0.05). The finding of GH levels intermediate between control and GH-deficient patients together with normal IGF-1 concentrations, questions the existence of a ‘classical’ GH insufficiency in TS girls. This study confirms that weight excess is a common feature of TS girls at pubertal age and suggests that the reduced GH secretion might be due, at least in part, to obesity.