Search

Objective: Isolated central precocious puberty (CPP) includes sporadic, familial and adoption-related forms, and the characterization of its etiology is challenging. This study investigated the prevalence and clinical characteristics of isolated CPP. Design and methods: This observational cohort study included all patients (n = 395) with CPP included in the database of a single academic pediatric care center over a period of 11.5 years. Results: In total, 332 of the 395 patients (84%) had isolated forms of CPP; the proportion of male patients was lower in this group than for non-isolated CPP (4 vs 33%, P < 0.0001). These patients had sporadic (n = 228, 68.5%), familial (n = 82, 25%) or adoption-related (n = 22, 6.5%) forms. Clinical characteristics at diagnosis were similar between groups, but girls with sporadic CPP were older at referral than those with familial or adoption-related CPP (P < 0.02), and birth weight SDS was lower in adopted patients than in those from the sporadic and familial groups (P < 0.01). In the 72 families containing patients with familial forms, both recessive and dominant transmissions were observed between first-degree relatives. Potential maternal or paternal transmission was identified in two-thirds of the studied families, in similar proportions. An autosomal dominant mode of transmission with low penetrance was suggested by the high proportion of affected parents (33 of the 72 families, 46%). Clinical presentation was similar whatever the mode of inheritance. Conclusion: These findings highlight the need for careful monitoring of the various forms of CPP. Future studies should explore pathophysiological mechanisms, particularly for familial forms. [ABSTRACT FROM AUTHOR]

A few hundred hypothalamic neurons form a complex network that controls reproduction in mammals by secreting gonadotropin-releasing hormone (GnRH). Timely postnatal changes in GnRH secretion are essential for pubertal onset. During the juvenile period, GnRH neurons undergo morphological remodeling, concomitantly achieving an increased responsiveness to kisspeptin, the main secretagogue of GnRH. However, the link between GnRH neuron activity and their morphology remains unknown. Here, we show that brain expression levels of Dmxl2, which encodes the vesicular protein rabconnectin-3α, determine the capacity of GnRH neurons to be activated by kisspeptin and estradiol. We also demonstrate that Dmxl2 expression levels control the pruning of GnRH dendrites, highlighting an unexpected role for a vesicular protein in the maturation of GnRH neuronal network. This effect is mediated by rabconnectin-3α in neurons or glial cells afferent to GnRH neurons. The widespread expression of Dmxl2 in several brain areas raises the intriguing hypothesis that rabconnectin-3α could be involved in the maturation of other neuronal populations. [ABSTRACT FROM AUTHOR]

Background: In March 2020, a 2-month lockdown of the entire population has been declared in France to limit the spread of COVID-19. Sudden changes in daily life can impact the glycemic control of patients with type 1 diabetes (T1D), especially children and adolescents. We aimed to assess the impact of the lockdown on glycemic control in children and adolescents with T1D., Methods: Children with T1D were prospectively recruited in two pediatric centers from May 11 to August 1, 2020. At inclusion, patients and/or parents were asked to fill in a form assessing the patient's lifestyle during the lockdown and a medical case report form was filled in by clinician. The mean of the three last glycated hemoglobin (HbA1c) values obtained before lockdown (HbA1c&#95;mean; before March 17, 2020) was compared to the first HbA1c value measured after the lockdown (HbA1c&#95;after; from May 11 to August 1, 2020). Univariable and multivariable analyses were performed, as appropriate, to identify factors associated with glycemic changes during lockdown., Results: One-hundred-and-eighteen children and adolescents (median age was 14.1 years, 50% males) with T1D (median time from diagnosis was 4.1 years) were enrolled in the study. No significant difference was observed between medians of HbA1c&#95;mean and HbA1c&#95;after values (8.37% [7.88; 9.32%] vs. 8.50% [7.70; 9.50%], respectively; p  = 0.391). Returning to the community was a protective factor [OR 0.31 (0.09-0.94); p  = 0.045]. Patients having increased HbA1c were more frequently in contact with a suspected case of COVID-19 [OR 9.07 (2.15-53.66); p  = 0.006], whereas patients having decreased HbA1c had the feeling of increase number of hypoglycemia [OR 0.19 (0.05-0.57); p  = 0.006]., Conclusion: In our patients, HbA1c before and after the lockdown was stable. In subgroup analysis, returning to the community was a protective factor. In addition, feeling of hypoglycemia was more frequent in the patients with decreased HbA1c., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Morat, Lucidarme, Gibert, Harbulot, Lachaume, Gréteau and Basmaci.)