The evolution of prolactinomas in children and adolescents continues to be controversial. Girls have more prevalence of microprolactinomas and their signs and symptoms are related to hyperprolactinemia and the resulting hypogonadotrophic hypogonadism. In males, the greater incidence of macroadenomas results in the presence of neuro-ophthalmologic signs. The larger prevalence of macroadenomas in males is consistent with findings in adults and would not be related to a later diagnosis. In patients with asymptomatic hyperprolactinemia, the presence of altered proportions of PRL isoforms should be evaluated. The diagnosis of prolactinoma requires both radiographic evidence of pituitary adenoma and laboratory analysis documenting the presence of sustained hyperprolactinemia. Because of their effectiveness and tolerance, dopaminergic agonists are the initial therapy of choice in pediatric age patients. Finally, molecular biology and genetic studies have brought new insights into the pathogenesis, clinical behavior and different therapeutic responses.

BackgroundIt is possible that genes on the X chromosome are expressed differently depending of its parental origin. The objective of this study was to determine the influence of the parental origin of the X-chromosome on phenotypic variability, response to rhGH and on the biochemical profile of TS patients.MethodsThis was a cross-sectional multicenter correlational study carried out over three years in six Latin-American university hospitals. Unrelated 45,X TS patients (n =  93; 18.3 ± 8.5 years )) were evaluated. A subgroup (n =  34) of the patients were prospectively treated with rhGH over two years. DNA profiles of patients and their mothers were compared to determine the parental origin of the retained X-chromosome through 10 polymorphic X-chromosome-STRs. The association with clinical features, biochemical profiles and anthropometric data at the beginning and after two years of rhGH treatment was determined.ResultsSeventy two percent of patients retained the maternal X chromosome (Xm). A trend towards significance between maternal height and patients final height (p ≤ 0.07) in 45,Xm subjects was observed. There was no correlation between paternal height and patient height. No differences were detected between both groups in regard to dysmorphic features, classical malformations or increase in the height-SDS after rhGH. There were higher levels of triglycerides, total and LDL cholesterol in patients >20 years who retained the Xm.ConclusionsThe parental origin of the retained X chromosome may influence lipid metabolism in TS patients, but its effect on growth seems to be minimal. No parental-origin-effect on the phenotypic features, associated anomalies and on the growth response to rhGH was found in 45,X TS individuals.

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Background: Glycosylated prolactin (G-PRL) is considered as the major post-translational modification of prolactin (PRL) showing reduced lactotropic and mitogenic activities compared to non-glycosylated prolactin (NG-PRL). Aim: To evaluate the evolution of G-PRL in normoprolactinemic children and adolescents and to analyze possible variations in glycosylated/total prolactin (T-PRL) ratios. Methods: T-PRL, G-PRL and NG-PRL were evaluated in 111 healthy female and male children and adolescents (4.1–18 years), classified as group 1 (Tanner I), group 2 (Tanner II–III) and group 3 (Tanner IV–V). G-PRL and NG-PRL were identified by chromatography on concanavalin-A-Sepharose. Results: G-PRL/T-PRL (median-range): females, group 1: 0.59 (0.17–0.77), group 2: 0.56 (0.31–0.78), group 3: 0.60 (0.38–0.79); males, group 1: 0.64 (0.39–0.80), group 2: 0.61 (0.24–0.79), group 3: 0.62 (0.35–0.90); the p value is not significant among the different groups in both genders. G-PRL/T-PRL ratios do not change when comparing low (first quartile) versus high (third quartile) T-PRL levels in the different groups. Conclusion: Our study would appear to support cosecretion of G-PRL and NG-PRL from childhood to the end of puberty. Such cosecretion would not be dependent on sex steroid levels. It is important to point out that puberty does not change the proportions of G-PRL and NG-PRL.

Aim: To evaluate melatonin secretion in a group of untreated and treated male growth hormone (GH)-deficient children and adolescents. Methods: We studied 44 male subjects: 8 untreated GH-deficient patients (GHDnt), 16 treated GH-deficient patients (GHDt) and 20 healthy children and adolescents as control group (CG). We measured urinary 6-sulfatoxymelatonin (6-SM) in total (24-hour samples), nocturnal (18.00-8.00 h) and diurnal samples (8.00-18.00 h). Levels of 6-SM were expressed as micrograms excreted per time interval and Δ values (difference between nighttime and daytime values). Results: Significant differences were observed among the 3 groups of pediatric subjects studied for total 6-SM (p < 0.0001), nocturnal 6-SM (p < 0.0001) and Δ values (p < 0.0001). Subsequent analysis showed significantly higher levels for total 6-SM, nocturnal 6-SM and nighttime-daytime Δ in the CG versus the GHDnt (p < 0.01) and in the CG versus the GHDt group (p < 0.01). No significant correlations were found between 6-SM excretion and insulin-like growth factor-1 values in the children and adolescents studied. Conclusions: GH-deficient patients showed lower levels of 6-SM. Our findings provide a different insight to a further understanding of some chronobiological disorders involved in GH deficiency in children.