New causes of central precocious puberty: the role of genetic factors

Differential Expression of RNAseq Imprinted Genes from Bovine Females Before and After Puberty

The productivity of beef cows depends on early reproduction traits such as puberty and has an economic impact on the efficiency of production system. Imprinted genes modulate many important endocrine processes such as growth, the onset of puberty and maternal reproductive and behavior. The role of imprinted genes in puberty is a challenging subject since they show the reciprocal role of maternal and paternal genomes in progeny. Although, there are evidences of the involvement of imprint genes in puberty in human, the role of this type of genes in the onset of puberty in cattle has not been studied yet. Here we examined the expression of 27 imprinted genes in pre and post puberty in a bovine model to find differentially expressed imprinted genes in maternal-paternal purebreds and reciprocal crosses across eight tissues and discussed the task of these genes in this crucial process of development and in onset of puberty. DLK1 and MKRN3 that previously described as cause of the central precocious puberty (CPP) in human were differentially expressed in this study. Functional annotation analysis of differentially imprinted genes in different tissues showed significant biological processes of cellular response to growth factor stimulus, response to growth factor, response to parathyroid hormone, developmental growth and the importance of alternative splicing. The results of this study have implications in understanding the role of imprinted genes in the onset of puberty in cattle.

Central precocious puberty: a review of diagnosis, treatment, and outcomes

Central precocious puberty (CPP) refers to early activation of the hypothalamic-pituitary-gonadal (HPG) axis and is manifested by breast development in girls or testicular enlargement in boys before the normal physiological age ranges. CPP can be precipitated by intracranial pathology, exposure to high levels of sex steroids, or environmental risk factors, but most cases are idiopathic. Monogenic causes have also been identified. In this Review, we summarise pathophysiology, risk factors, diagnosis, and management of CPP. Concern for CPP should prompt referral to paediatric endocrinology where diagnosis is confirmed by clinical, biochemical, radiological, and genetic testing. CPP is treated with a gonadotropin-releasing hormone analogue, the primary aims of which are to increase adult height and postpone development of secondary sexual characteristics to an age that is more commensurate with peers. Although long-term outcomes of treatment with gonadotropin-releasing hormone analogues are reassuring, additional research on the psychological effect of CPP is needed.

Clinical Management and Therapy of Precocious Puberty in the Sapienza University Pediatrics Hospital of Rome, Italy

Puberty identifies the transition from childhood to adulthood. Precocious puberty is the onset of signs of pubertal development before age eight in girls and before age nine in boys, it has an incidence of 1/5000-1/10,000 with an F:M ratio ranging from 3:1 to 20:1. Precocious puberty can be divided into central, also known as gonadotropin-dependent precocious puberty or true precocious puberty, and peripheral, also recognized as gonadotropin-independent precocious puberty or precocious pseudopuberty. Thus, the main aim of this narrative report is to describe the standard clinical management and therapy of precocious puberty according to the experience and expertise of pediatricians and pediatric endocrinologists at Policlinico Umberto I, Sapienza University of Rome, Italy. In the suspicion of early sexual maturation, it is important to collect information regarding the age of onset, the speed of maturation of secondary sexual features, exposure to exogenous sex steroids and the presence of neurological symptoms. The objective examination, in addition to the evaluation of secondary sexual characteristics, must also include the evaluation of auxological parameters. Initial laboratory investigations should include serum gonadotropin levels (LH and FSH) and serum levels of the sex steroids. Brain MRI should be performed as indicated by the 2009 Consensus Statement in all boys regardless of chronological age and in all girls with onset of pubertal signs before 6 years of age. The gold standard in the treatment of central precocious puberty is represented by GnRH analogs, whereas, as far as peripheral forms are concerned, the triggering cause must be identified and treated. At the moment there are no reliable data establishing the criteria for discontinuation of GnRH analog therapy. However, numerous pieces of evidence suggest that the therapy should be suspended at the physiological age at which puberty occurs.

Leuprolide and triptorelin treatment in children with idiopathic central precocious puberty: an efficacy/tolerability comparison study

Introduction

Central precocious puberty (CPP) results from premature activation of hypothalamic-pituitary-gonadal axis, with the consequent increase of gonadotropin-releasing hormone (GnRH); GnRH agonists (GnRHa) represent the gold-standard therapy in children with CPP although their use might be responsible for pituitary GnRH receptors down-regulation, that in turn suppresses luteinizing hormone (LH) and follicle stimulating hormone (FSH) and blocks of gonadal sex hormones release. The most prescribed GnRHa in the clinical practice are leuprolide and triptorelin, whose use is generally safe and well tolerated; however, mild menopausal-like side effects could appear. The aim of the present study was to investigate and compare the efficacy and tolerability profile of leuprolide and triptorelin in CPP patients.

Methods

110 girls affected by CPP were enrolled in this retrospective study, carried out from 2018 to 2020. The enrolled patients received leuprolide (n = 48) or triptorelin (n = 62). Efficacy was investigated by the means of clinical parameters and radiological changes and side effects were also recorded to evaluate the possible relationship between the two GnRHa treatments and side effects appearance.

Results

At baseline triptorelin patients had significantly higher LH and LH peak levels than leuprolide patients, whereas no significant difference in other patient characteristics was observed between the two groups. The leuprolide treatment lasted 971 days [790-1,171 days] while the duration of triptorelin administration was 792 days [760-1,003 days] (p < 0.001). Overall 46 (41.8%) of the studied patients reported mild menopausal-like symptoms: among these 27 were treated with triptorelin and 19 with leuprolide (p = 0.558). Patients treated with triptorelin, or leuprolide showed headache (27.4% vs. 16.7%), mood swings (12.9% vs. 16.7%), increased appetite (12.9% vs. 18.8%) and nausea (1.6% vs. 10.4%) respectively. Moreover, the onset of side effects appearance related to GnRHa therapy significantly reduces with the increase of the initial bone age (p = 0.038).

Conclusion

Leuprolide and triptorelin treatment appear to be effective and safe without significant difference between the two drugs in term of efficacy and tolerability, making both good options for treating CPP.

A new DLK1 defect in a family with idiopathic central precocious puberty: elucidation of the male phenotype

PURPOSE

We aimed to investigate a cohort of female and male patients with idiopathic central precocious puberty (CPP), negative for Makorin Ring Finger Protein 3 (MKRN3) defect, by molecular screening for Delta-like 1 homolog (DLK1) defects. DLK1 is an imprinted gene, whose mutations have been described as a rare cause of CPP in girls and adult women with precocious menarche, obesity and metabolic derangement.

METHODS

We enrolled 14 girls with familial CPP and 13 boys with familial or sporadic CPP from multiple academic hospital centers. Gene sequencing of DLK1 gene was performed. Circulating levels of DLK1 were measured and clinical and biochemical characteristics were described in those with DLK1 defects.

RESULTS

A novel heterozygous mutation in DLK1, c.288_289insC (p.Cys97Leufs*16), was identified in a male proband, his sister and their father. Age at onset of puberty was in line with previous reports in the girl and 8 years in the boy. The father with untreated CPP showed short stature. No metabolic derangement was present in the father except hypercholesterolemia. Undetectable Dlk1 serum levels indicated the complete lack of protein production in the three affected patients.

CONCLUSION

A DLK1 defect has been identified for the first time in a boy, underscoring the importance of genetic testing in males with idiopathic or sporadic CPP. The short stature reported by his untreated father suggests the need for timely diagnosis and treatment of subjects with DLK1 defects.

Oestrogenic Activity in Girls with Signs of Precocious Puberty as Exposure Biomarker to Endocrine Disrupting Chemicals: A Pilot Study

The relationship between endocrine disrupting chemical (EDC) exposure and Precocious Puberty (PP) was investigated in this pilot study, involving girls with signs of PP (P) and pre-pubertal girls (C). Risk factors for PP were assessed through questionnaires, while 17β-oestradiol (E2) levels and oestrogenic activity were quantified on sera. The oestrogenic activity, expressed as E2 equivalent concentration (EEQ), was applied as EDC exposure biomarker. Questionnaires showed a low EDC knowledge, a high EDC exposure, and a potential relationship between some habits at risk for EDC exposure and PP. EEQs were similar between C and P; however, they were significantly higher in girls living in an urban environment than in girls living in a rural environment, suggesting a potential higher EDC exposure in cities. The results of this pilot study highlighted the need to raise awareness on EDCs and can be considered a starting point to clarify the relationship between EDC exposure and PP.

Effect of CPP-related genes on GnRH secretion and Notch signaling pathway during puberty

Puberty is a complex biological process of sexual development, influenced by genetic, metabolic-nutritional, environmental and socioeconomic factors, characterized by the development of secondary sexual characteristics, maturation of the gonads, leading to the acquisition of reproductive capacity. The onset of central precocious puberty (CPP) is mainly associated with the early activation of the hypothalamic-pituitary-gonadal (HPG) axis and increased secretion of gonadotropin-releasing hormone (GnRH), leading to increased pituitary secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and activation of gonadal function. Due to the expense and invasiveness of current diagnostic testing and drug therapies for CPP, it would be helpful to find serum and genetic markers to facilitate diagnosis. In this paper, we summarized the related factors that may affect the expression of GnRH1 gene and the secretion and action pathway of GnRH and related sex hormones, and found several potential targets, such as MKRN3, DLK1 and KISS1. Although, the specific mechanism still needs to be further studied, we would be encouraged if the insights from this review could provide new insights for future research and clinical diagnosis and treatment of CPP.

Aberrant Notch Signaling Pathway as a Potential Mechanism of Central Precocious Puberty

The Notch signaling pathway is highly conserved during evolution. It has been well documented that Notch signaling regulates cell proliferation, migration, and death in the nervous, cardiac, and endocrine systems. The Notch pathway is relatively simple, but its activity is regulated by numerous complex mechanisms. Ligands bind to Notch receptors, inducing their activation and cleavage. Various post-translational processes regulate Notch signaling by affecting the synthesis, secretion, activation, and degradation of Notch pathway-related proteins. Through such post-translational regulatory processes, Notch signaling has versatile effects in many tissues, including the hypothalamus. Recently, several studies have reported that mutations in genes related to the Notch signaling pathway were found in patients with central precocious puberty (CPP). CPP is characterized by the early activation of the hypothalamus–pituitary–gonadal (HPG) axis. Although genetic factors play an important role in CPP development, few associated genetic variants have been identified. Aberrant Notch signaling may be associated with abnormal pubertal development. In this review, we discuss the current knowledge about the role of the Notch signaling pathway in puberty and consider the potential mechanisms underlying CPP.

The Role of Pediatric Nutrition as a Modifiable Risk Factor for Precocious Puberty

Puberty is a critical phase of growth and development characterized by a complex process regulated by the neuroendocrine system. Precocious puberty (PP) is defined as the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal. The timing of puberty has important public health, clinical, and social implications. In fact, it is crucial in psychological and physical development and can impact future health. Nutritional status is considered as one of the most important factors modulating pubertal development. This narrative review presents an overview on the role of nutritional factors as determinants of the timing of sexual maturation, focusing on early-life and childhood nutrition. As reported, breast milk seems to have an important protective role against early puberty onset, mainly due to its positive influence on infant growth rate and childhood overweight prevention. The energy imbalance, macro/micronutrient food content, and dietary patterns may modulate the premature activation of the hypothalamic-pituitary-gonadal axis, inducing precocious activation of puberty. An increase in knowledge on the mechanism whereby nutrients may influence puberty will be useful in providing adequate nutritional recommendations to prevent PP and related complications.

Identification of differentially expressed genes associated with precocious puberty by suppression subtractive hybridization in goat pituitary tissues

The aim of this study was to identify genes related to precocious puberty expressed in the pituitary of goats at different growth stages by suppression subtractive hybridization (SSH). The pituitary glands from Jining Gray (JG) goats (early puberty) and Liaoning Cashmere (LC) goats (late puberty) at 30, 90, and 180 days were used in this study. To identify differentially expressed genes (DEGs) in the pituitary glands, mRNA was extracted from these tissues, and SSH libraries were constructed and divided into the following groups: juvenile group (30-JG vs. 30-LC, API), puberty group (90-JG vs. 180-LC, BPI), and control group (90-JG vs. 90-LC, EPI). A total of 60, 49, and 58 DEGs were annotated by 222 Gene Ontology (GO) terms and 75 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Most of the DEGs were significantly enriched in GO terms related to 'structural constituent of ribosome', 'translation' and 'GTP binding', and numerous DEGs were also significantly enriched in KEGG terms related to the Jak-STAT signaling and oocyte meiosis pathways. Candidate genes associated with precocious puberty and sexual development were screened from the SSH libraries. These genes were analyzed to determine if they were expressed in the pituitary tissues of the goats at different growth stages and to identify genes that may influence the hypothalamic-pituitary-gonadal (HPG) axis. In this study, we found precocious puberty-related genes (such as PRLP0, EIF5A, and YWHAH) that may be interesting from an evolutionary perspective and that could be investigated for use in future goat breeding programs. Our results provide a valuable dataset that will facilitate further research into the reproductive biology of goats.

Elevated expression of MKRN3 in squamous cell carcinoma of the head and neck and its clinical significance

BACKGROUND

Squamous cell carcinoma of the head and neck (SCCHN) is one of the most common types of cancer that cause a substantial number of cancer-related deaths. Our previous study has revealed that makorin ring finger protein 3 (MKRN3) may act as a key regulator of the SCCHN tumorigenesis; however, its specific role in SCCHN progression has not been reported.

METHODS

The Cancer Genome Atlas (TCGA) data analysis and quantitative polymerase chain reaction (qPCR) were used to quantify the MKRN3 mRNA expression levels in SCCHN; immunohistochemical staining or immunoblotting analyses were performed to detect MKRN3 protein expression. Kaplan-Meier plotter was used to assess the prognostic values of MKRN3 in terms of overall survival and disease-free survival. The expression differences based on various clinicopathological features were evaluated using subgroup analysis and forest map analysis. The regulatory mechanism of MKRN3 was further investigated using gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Subsequently, STRING was used to perform a co-expression and enrichment analysis for MKRN3. Homologous modeling, molecular docking, and western blot analyses were performed to investigate the relationship between MKRN3 and its potential target gene P53.

RESULTS

MKRN3 was ectopically expressed between cancerous and noncancerous SCCHN tissues, and its expression level was tightly associated with high T classifications as well as advanced clinical stages. qPCR analysis revealed that MKRN3 was upregulated in the SCCHN cell line. Moreover, Kaplan-Meier and Cox regression analyses indicated that SCCHN patients with high MKRN3 expression had poorer prognosis and that MKRN3 was a potential prognostic marker for SCCHN. Using gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses, we determined that MKRN3 may be involved in the regulation of synthesis and metabolism and cell growth, death and motility, as well as cancer pathways associated with SCCHN progression. Mechanism investigation further revealed that P53, a potential target of MKRN3, may be involved in the SCCHN tumorigenesis mediated by MKRN3.

CONCLUSIONS

We performed a comprehensive evaluation of the clinical significance of MKRN3 and explored its underlying mechanisms. We concluded that MKRN3 represents a valuable predictive biomarker and potential therapeutic target in SCCHN.

Biological clock and heredity in pubertal timing: what is new?

Puberty represents a milestone during a person's life and is characterized by several physical and psychological changes which end with the achievement of sexual maturation and of fertility. Puberty onset depends on a series of sophisticated, not completely understood, mechanisms certainly involving Gonadotropin-Releasing Hormone (GnRH) and its effects on pituitary gonadotropins. As recent evidence has demonstrated that pubertal timing deeply affects future adult health life, much efforts have been performed in order to clarify the exact actors involved in the onset and progression of puberty. Genetic factors are undoubtedly essential players in the regulation of pubertal development, accounting for approximately 50-80% of its variability. Mutations in genes such as KISS1, MKRN3 and DLK1 have been associated with central precocious puberty. Interestingly, a possible involvement of epigenetic mechanisms has been proposed as additional element able to affect pubertal phase. Environmental factors have recently attracted much attention. Indeed, an overall decrease in the age of puberty has been observed in the last decades. As genetic factors require long time to exert their effect, other players, such as environmental ones, may be involved. Special focus has been posed on nutritional status, endocrine-disrupting chemicals with non-conclusive results. Pubertal timing deeply affects future life, suggesting the need to clarify mechanisms driving pubertal onset and progression, in order to identify tailored therapeutic strategies and targets.

Long-term efficacy and safety of gonadotropin-releasing hormone analog treatment in children with idiopathic central precocious puberty: A systematic review and meta-analysis

OBJECTIVE

To investigate the long-term efficacy and safety of gonadotropin-releasing hormone analog (GnRHa) treatment in children with idiopathic central precocious puberty (CPP).

METHOD

The protocol was registered with International Prospective Register of Systematic Reviews (CRD42018102792). PubMed, EMBASE and the Cochrane Library were searched for eligible comparative and single-arm studies.

RESULTS

We identified a total of 98 studies that included 5475 individuals. The overall risk of bias of the eligible studies ranged from critical to moderate. The overall quality of evidence for each outcome ranged from very low to moderate. Evidence-based comparative studies showed that GnRHa treatment increase final adult height (FAH, cm; studies = 4, n = 242; mean difference [MD] = 4.83; 95% confidence interval [CI], 2.32 to 7.34; I²  = 49%) and decrease body mass index (BMI, kg/m² ; studies = 3, n = 334; MD = -1.01; 95% CI, -1.64 to -0.37; I²  = 0%) in girls with idiopathic CPP compared with no treatment. The incidence of polycystic ovary syndrome (PCOS) did not significantly differ with and without GnRHa treatment (studies = 3, n = 179; risk ratio = 1.21; 95% CI, 0.46 to 3.15; I²  = 48%). The evidence for other long-term outcomes was very weak to deduce the effects of GnRHa treatment. Further, limited evidence is available on its effects in boys.

CONCLUSION

Compared with no treatment, evidence indicates that GnRHa treatment increase FAH and decrease BMI in girls with idiopathic CPP. GnRHa treatment did not evidently increase the risk of PCOS. However, evidence regarding other key long-term outcomes (such as infertility and malignant or metabolic diseases) was considered very weak to suggest the benefits or side effects of GnRHa treatment. Additional high-quality evidence is needed before firm conclusions can be drawn.

Central Precocious Puberty in Boys and Girls: Similarities and Differences

Central precocious puberty (CPP) is due to the premature activation of the hypothalamic–pituitary–gonadal axis, which is responsible for the appearance of secondary sexual characteristics. It occurs before the age of 8 and 9 in girls and boys, respectively. CPP shows higher incidence in females than in males. Causes of CPP are similar in both sexes, but the idiopathic form is more frequent in girls, while organic forms are more frequent in males. Recent studies demonstrated a role of some genetic variants in the pathogenesis of CPP. The diagnostic evaluation based on accurate physical examination, assessment of the pituitary–gonadal axis, pelvic sonography in girls, and determination of bone age. Magnetic resonance of the central nervous system should be done in all boys and selected girls. Since the 1980s, pharmacologic treatment involves the use of gonadotropin-releasing hormone (GnRH) analogs. These drugs are characterized by few side effects and long-term safety. Many data are available on the outcome of GnRH analog treated female patients, while poor data are reported in boys. Adult height is improved in both sexes.

Syndromic Disorders Caused by Disturbed Human Imprinting

Imprinting disorders are a group of congenital diseases caused by dysregulation of genomic imprinting, affecting prenatal and postnatal growth, neurocognitive development, metabolism and cancer predisposition. Aberrant expression of imprinted genes can be achieved through different mechanisms, classified into epigenetic - if not involving DNA sequence change - or genetic in the case of altered genomic sequence. Despite the underlying mechanism, the phenotype depends on the parental allele affected and opposite phenotypes may result depending on the involvement of the maternal or the paternal chromosome. Imprinting disorders are largely underdiagnosed because of the broad range of clinical signs, the overlap of presentation among different disorders, the presence of mild phenotypes, the mitigation of the phenotype with age and the limited availability of molecular techniques employed for diagnosis. This review briefly illustrates the currently known human imprinting disorders, highlighting endocrinological aspects of pediatric interest.

Evaluation of Serum Makorin Ring Finger Protein 3 (MKRN3) Levels in Girls With Idiopathic Central Precocious Puberty and Premature Thelarche

This study aims to investigate serum makorin ring finger protein 3 (MKRN3) levels in girls with idiopathic central precocious puberty (ICPP) and premature thelarche (PT), in order to determine whether circulating MKRN3 level is associated with ICPP and PT. A total of 90 girls were enrolled in the study. 30 age-matched girls were allocated for each group (ICPP, PT and healthy controls [HC], respectively). The base LH (B-LH) and E2 levels were higher in ICPP girls than those in HC and PT girls. The peak LH (P-LH) levels and P-LH/P-FSH values were obviously higher in ICPP girls than those in PT girls, while higher peak FSH (P-FSH) levels were detected in PT girls when compared to those in ICPP girls. Kisspeptin levels were lower in HC girls than those in ICPP and PT girls. MKRN3 levels were the highest in HC girls among the three groups. There were relatively strong negative correlations among MKRN3, kisspeptin and P-LH/P-FSH. Circulating MKRN3 can have an important role in the onset of ICPP and PT. However, this should not be used as an independent diagnostic criterion for diagnosing ICPP or differentiating ICPP from PT, but should be used only as an adjunctive diagnostic biomarker.

Outcomes of Patients with Central Precocious Puberty Due to Loss-of-Function Mutations in the MKRN3 Gene after Treatment with Gonadotropin-Releasing Hormone Analog

INTRODUCTION

Loss-of-function mutation of MKRN3 represents the most frequent genetic cause of familial central precocious puberty (CPP). The outcomes of gonadotropin-releasing hormone analog (GnRHa) treatment in CPP patients with MKRN3 defects are unknown.

OBJECTIVE

To describe the clinical and hormonal features of patients with CPP with or without MKRN3 mutations after GnRHa treatment. Anthropometric, metabolic and reproductive parameters were evaluated.

PATIENTS AND METHODS

Twenty-nine female patients with CPP due to loss-of-function mutations in the MKRN3 and 43 female patients with idiopathic CPP were included. Their medical records were retrospectively evaluated for clinical, laboratory, and imaging study, before, during, and after GnRHa treatment. All patients with idiopathic CPP and 11 patients with CPP due to MKRN3 defects reached final height (FH).

RESULTS

At the diagnosis, there were no significant differences between clinical and laboratory features of patients with CPP with or without MKRN3 mutations. A high prevalence of overweight and obesity was observed in patients with CPP with or without MKRN3 mutations (47.3 and 50%, respectively), followed by a significant reduction after GnRHa treatment. No significant differences in the values of mean FH and target height were found between the 2 CPP groups after GnRHa treatment. Menarche occurred at the expected age in patients with or without CPP due to MKRN3 mutations (11.5 ± 1.3 and 12 ± 0.6 years, respectively). The prevalence of polycystic ovarian syndrome was 9.1% in patients with CPP due to MKRN3 mutations and 5.9% in those with idiopathic CPP.

CONCLUSION

Anthropometric, metabolic, and reproductive outcomes after GnRHa treatment were comparable in CPP patients, with or without MKRN3 mutations, suggesting the absence of deleterious effects of MKRN3 defects in young female adults' life.

p53 Mediates GnRH Secretion via Lin28/let-7 System in GT1-7 Cells

STUDY OBJECTIVE

The well-known tumor suppressor transcriptional factor p53 has been proposed to be one of the central hubs of a functionally related and hierarchically arranged gene network coordinating pubertal timing. Our previous studies revealed that p53 is involved in the metabolic control of puberty. The current study aimed to investigate the underlying signaling pathway, through which p53 mediated the metabolic control of puberty.

DESIGN SETTING PARTICIPANTS INTERVENTIONS AND MAIN OUTCOME MEASURES

We engineered the expression of p53 and/or Lin28a in GT1-7 cells to investigate the interaction between p53 and Lin28/let-7 system, and their impact on GnRH secretion.

RESULTS

Overexpression of p53 stimulated, while inhibition of p53 by pifithrin-α significantly suppressed the GnRH secretion and GPR54 expression levels in response to kisspeptin stimulation in GT1-7 cells. Furthermore, overexpressed p53 suppressed Lin28a and c-Myc expression levels and increased let-7 expression levels in GT1-7 cell lines. On the other hand, inhibition of p53 by pifithrin-α upregulated Lin28a and c-Myc levels and downregulated let-7 expression levels. Moreover, Lin28a overexpression counteracted the effect of p53 overexpression in p53 and Lin28a co-overexpression cells, whose GnRH secretion and GPR54 expression levels were not different from controls. Meanwhile, Lin28a suppression counteracted the effect of pifithrin-α, and the GnRH secretion and GPR54 expression levels are not different from controls in p53 and Lin28a co-suppression cells.

CONCLUSION

These data suggest that p53 is a central mediator of GnRH secretion in hypothalamus, and this effect is at least partly through the Lin28/let-7 pathway.

Health Care Utilization and Economic Burden in Patients with Central Precocious Puberty: An Assessment of the Commercially Insured and Medicaid Populations

BACKGROUND

Central precocious puberty (CPP), early onset of puberty caused by the premature activation of the hypothalamic-pituitary-gonadal axis, is a rare disease affecting children of both sexes. There is limited evidence that quantifies the economic burden of CPP.

OBJECTIVE

To characterize the health care resource utilization (HRU) and costs among patients with CPP who were treated with gonadotropinreleasing hormone (GnRH) agonists, for those insured commercially and with Medicaid.

METHODS

Eligible CPP patients for this retrospective cohort analysis were aged ≤ 12 years; were diagnosed between January 1, 2010, and September 30, 2014; and had at least 1 prescription for an FDA-approved GnRH agonist: leuprolide or histrelin (first prescription = index date). CPP patients had to be continuously enrolled in the MarketScan Commercial or Medicaid Database for at least 12 months before and after the index date. Control patients were randomly selected from all eligible non-CPP patients and N:1 matched on demographic characteristics with up to 20 controls per case. Clinical comorbidities, HRU, and costs were compared between study cohorts. Health care costs were examined via multivariable analysis to adjust for baseline differences between patients and controls. Treatment patterns among CPP patients were also characterized.

RESULTS

There were 1,236 CPP patients and 24,206 controls with commercial insurance and 673 CPP patients and 11,965 controls with Medicaid insurance who met the inclusion criteria. Across payers, the mean age of CPP patients ranged from 7.6 years (Medicaid) to 8.5 (commercial), and 80%-87% were female. The mean observed duration (SD) of treatment with any approved GnRH agonist was 1.51 (0.98) years for commercial patients and 1.22 (1.04) for Medicaid patients. The mean age of discontinuation among patients who ceased GnRH agonist treatment ranged from 8.7 to 9.6 years. In the first year post-index, CPP patients had a greater number of unique diagnosis codes, unique medications, and comorbid conditions than controls. They also had significantly higher all-cause and diseasemonitoring related HRU. After adjusting for baseline characteristics, CPP patients with Medicaid insurance spent 6.42 times more ($16,768 [$31,460] vs. $2,610 [$4,897]), and patients with commercial insurance spent 12.25 times more ($19,940 [$20,132] vs. $1,628 [$1,645]) on health care in the year following treatment initiation than matched controls.

CONCLUSIONS

Patients with CPP have substantially more comorbidities and greater HRU and costs than their non-CPP peers.

DISCLOSURES

All funding for this study was provided by AbbVie, which participated in analysis and interpretation of data, drafting, reviewing, and approving the publication. All authors contributed to the development of the publication and maintained control over the final content. Soliman and Grubb are employed by AbbVie and hold stock in AbbVie. Bonafede and Nelson are employed by IBM Watson Health, which received funding from AbbVie to conduct this study. Klein is a paid consultant of AbbVie but was not compensated for any work on development of this manuscript for publication. Portions of this work were presented at Pediatric Academic Societies (PAS) 2018 Meeting, May 5-8, 2018, in Toronto, Canada, as a poster presentation titled "Examination of Economic Burden Among Commercially Insured Patients with Central Precocious Puberty (CPP)."

Long-term effects and significant Adverse Drug Reactions (ADRs) associated with the use of Gonadotropin-Releasing Hormone analogs (GnRHa) for central precocious puberty: a brief review of literature

Central precocious puberty (CPP) is defined as an early pubertal development that occurs before the age of 9 years in boys and 8 years in girls. It results from premature activation of the hypothalamic-pituitary-gonadal axis. Gonadotropin-releasing hormone agonists (GnRHa) have been the gold standard therapy for CPP for more than 30 years. These compounds have a high affinity for the pituitary LHRH receptor and are resistant to enzymatic degradation. Through continuous stimulation, GnRHa inhibit the pulsatile secretion of gonadotropin, resulting in hormonal suppression, cessation of pubertal development, and normalization of growth and skeletal maturation rates. The goal of therapy is to halt pubertal progression and delay epiphyseal maturation that leads to improvement of final adult height. There are no widely accepted guidelines for how long to continue treatment with a GnRHa for CPP, and individual practice varies widely. Furthermore, conflicting results have been published on the long-term effects of GnRHa therapy in patients with CPP. Therefore, we reviewed the current literature focusing our attention on the long-term effects and the significant adverse drug reactions (ADRs) observed during treatment with GnRHa in patients with CPP. Our review may provide the necessary data to enable clinicians to administer GnRHa in the safest and most appropriate way. Further studies are necessary to identify the mechanisms of development of potential adverse drug reactions related to GnRHa therapy in CPP.

MKRN3 Mutations in Central Precocious Puberty: A Systematic Review and Meta-Analysis

MKRN3 mutations represent the most common genetic cause of central precocious puberty (CPP) but associations between genotype and clinical features have not been extensively explored. This systematic review and meta-analysis investigated genotype-phenotype associations and prevalence of MKRN3 mutations in CPP. The search was conducted in seven electronic databases (Cochrane, EMBASE, LILACS, LIVIVO, PubMed, Scopus, and Web of Science) for articles published until 4 September 2018. Studies evaluating MKRN3 mutations in patients with CPP were considered eligible. A total of 22 studies, studying 880 subjects with CPP, fulfilled the inclusion criteria. Eighty-nine subjects (76 girls) were identified as harboring MKRN3 mutations. Girls, compared with boys, exhibited earlier age at pubertal onset (median, 6.0 years; range, 3.0 to 7.0 vs 8.5 years; range, 5.9 to 9.0; P < 0.001), and higher basal FSH levels (median, 4.3 IU/L; range, 0.7 to 13.94 IU/L vs 2.45 IU/L; range, 0.8 to 13.70 IU/L; P = 0.003), and bone age advancement (ΔBA; median, 2.3 years; range, -0.9 to 5.2 vs 1.2 years; range, 0.0 to 2.3; P = 0.01). Additional dysmorphisms were uncommon. A total of 14 studies evaluating 857 patients were included for quantitative analysis, with a pooled overall mutation prevalence of 9.0% (95% CI, 0.04 to 0.15). Subgroup analysis showed that prevalence estimates were higher in males, familial cases, and in non-Asian countries. In conclusion, MKRN3 mutations are associated with nonsyndromic CPP and manifest in a sex-dimorphic manner, with girls being affected earlier. They represent a common cause of CPP in western countries, especially in boys and familial cases.

Evolutionary Analysis of Makorin Ring Finger Protein 3 Reveals Positive Selection in Mammals

Makorin ring finger proteins (MKRNs) are part the of ubiquitin-proteasome system; a complex system important for cell functions. Ubiquitin fate through proteolytic, non-proteolytic pathways varies, depending on covalent linkage between ubiquitin and protein substrates. Makorin ring finger protein 3 is an integral part of covalent linkage of ubiquitin to protein substrates. Similar to others imprinted genes, MKRN3 also evolve under positive selection; however, which codons are specifically selected in MKRN3 during evolution are needed to be explored. Different maximum-likelihood (ML) codon-based methodologies were used to ascertain positive selection signatures in 22 mammalian sequences of MKRN3 to probe an individual codon for positive selection signatures. By applying the HyPhy software package implemented in the Data Monkey Web Server and CODEML implemented in PAML, evolutionary analysis based on two Ml frameworks were conducted. The analysis was executed by comparing M1a against M2a, M7 against M8, and PAML models and 2∆Lnl (LRT) was resulted by likelihood logs. M1a contributed ω1 (dN/dS) with LRT value (∆Lnl) 12.01, and positive selection was found in M2a with ω3 = 2.23603. To further improve selection test, M8 was compared to M7 with 2∆Lnl (LRT) 30.17, and M8 showed positive selection with ω = 1.55759. The data were fit to M8 than M7, which suggests that M8 was the most significant model of selection. M8 was judged encouraging for this analysis and used to establish a positive selection of MKRN3 proteins. We found Gly312 as a positively selected amino acid in a zinc finger motif/Really Interesting New Gene (RING) finger motif; the former ones’ region is involved in RNA binding and the later ones in ubiquitin ligase activity of the protein, vital for protein function. Selection analyses of MKRNs might advance the developments in unique approaches that could lead to genetic progress over the selection of superior individuals with the breeding values higher for certain traits as ancestries to get the next generation.

Central precocious puberty in girls: Diagnostic study and auxological response to triptorelin treatment

INTRODUCTION

There are several controversies regarding the diagnostic tests and management of central precocious puberty (CPP). The aim of this study is to present the experience acquired in a group of girls with CPP treated with triptorelin, and to analyze the auxological characteristics and diagnostic tests.

MATERIAL AND METHODS

An observational, retrospective study in a group of 60 girls with CPP was conducted between January 2010 and December 2017. Sociodemographic, auxological and hormonal data were recorded at diagnosis, and pelvic ultrasound and magnetic resonance imaging of the head were performed. Girls were treated with triptorelin and monitored after treatment discontinuation until menarche.

RESULTS

At treatment start, chronological age and bone age were 7.7±0.7 and 9.7±0.8 years respectively, and growth velocity was 8.3±1.6cm/year. Target height was 161.1±5.8cm. Peak LH level after stimulation was 16.6±12.1 IU/l. Ovarian volumes were greater than 3mL in 35% of cases. MRI of the head was pathological in seven girls (11.7%). At treatment completion, chronological age and bone age were 10.3±1.1 and 11.2±0.8 years respectively, and growth velocity was 4.7±1.4cm/year. At the age of menarche (11.9±0.9 years), height was 157.5±5.7cm.

CONCLUSIONS

Treatment of CPP with triptorelin appears to be beneficial. The possibility to block pubertal development and slow skeletal maturation allows patients to reach their target height. However, individualized auxological monitoring would be mandatory.

Central Precocious Puberty Caused by Novel Mutations in the Promoter and 5'-UTR Region of the Imprinted MKRN3 Gene

Background: Central Precocious Puberty (CPP) is clinically defined by the development of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys. To date, mutations in the coding region of KISS1, KISS1R, PROKR2, DLK1, and MKRN3 genes have been reported as causative for CPP. This study investigated the presence of causative mutations in both the promoter and the 5'-UTR regions of the MKRN3 gene. Methods: Sanger DNA sequencing was used for screening the proximal promoter and 5'-UTR region of the MKRN3 gene in a group of 73 index girls with CPP. Mutations identified were cloned in luciferase reporter gene vectors and transiently transfected in GN11 cells in order to check for changes in the activity of the MKRN3 promoter. GN11 cells were previously checked for Mkrn3 expression using lentivirus mediated knock-down. In silico analysis was implemented for the detection of changes in the mRNA secondary structure of the mutated MKRN3 5'-UTR. Results: Three novel heterozygous mutations (-166, -865, -886 nt upstream to the transcription start site) located in the proximal promoter region of the MKRN3 gene were identified in six non-related girls with CPP. Four of these girls shared the -865 mutation, one the -166, and another one the -886. A 5'-UTR (+13 nt downstream to the transcription start site) novel mutation was also identified in a girl with similar clinical phenotype. Gene reporter assay evaluated the identified promoter mutations and demonstrated a significant reduction of MKRN3 promoter activity in transfected GN11 cells. In silico analysis for the mutated 5'-UTR predicted a significant change of the mRNA secondary structure. The minimum free energy (MFE) of the mutated 5'-UTR was higher when compared to the corresponding wild-type indicating less stable RNA secondary structure. Conclusion: Our findings demonstrated novel genetic alterations in the promoter and 5'-UTR regulatory regions of the MKRN3 gene. These changes add to another region to check for the etiology of CPP.

Timing mechanism of sexually dimorphic nervous system differentiation

The molecular mechanisms that control the timing of sexual differentiation in the brain are poorly understood. We found that the timing of sexually dimorphic differentiation of postmitotic, sex-shared neurons in the nervous system of the Caenorhabditis elegans male is controlled by the temporally regulated miRNA let-7 and its target lin-41, a translational regulator. lin-41 acts through lin-29a, an isoform of a conserved Zn finger transcription factor, expressed in a subset of sex-shared neurons only in the male. Ectopic lin-29a is sufficient to impose male-specific features at earlier stages of development and in the opposite sex. The temporal, sexual and spatial specificity of lin-29a expression is controlled intersectionally through the lin-28/let-7/lin-41 heterochronic pathway, sex chromosome configuration and neuron-type-specific terminal selector transcription factors. Two Doublesex-like transcription factors represent additional sex- and neuron-type specific targets of LIN-41 and are regulated in a similar intersectional manner.

Methylome profiling of healthy and central precocious puberty girls

Background

Recent studies demonstrated that changes in DNA methylation (DNAm) and inactivation of two imprinted genes (MKRN3 and DLK1) alter the onset of female puberty. We aimed to investigate the association of DNAm profiling with the timing of human puberty analyzing the genome-wide DNAm patterns of peripheral blood leukocytes from ten female patients with central precocious puberty (CPP) and 33 healthy girls (15 pre- and 18 post-pubertal). For this purpose, we performed comparisons between the groups: pre- versus post-pubertal, CPP versus pre-pubertal, and CPP versus post-pubertal.

Results

Analyzing the methylome changes associated with normal puberty, we identified 120 differentially methylated regions (DMRs) when comparing pre- and post-pubertal healthy girls. Most of these DMRs were hypermethylated in the pubertal group (99%) and located on the X chromosome (74%). Only one genomic region, containing the promoter of ZFP57, was hypomethylated in the pubertal group. ZFP57 is a transcriptional repressor required for both methylation and imprinting of multiple genomic loci. ZFP57 expression in the hypothalamus of female rhesus monkeys increased during peripubertal development, suggesting enhanced repression of downstream ZFP57 target genes. Fourteen other zinc finger (ZNF) genes were related to the hypermethylated DMRs at normal puberty. Analyzing the methylome changes associated with CPP, we demonstrated that the patients with CPP exhibited more hypermethylated CpG sites compared to both pre-pubertal (81%) and pubertal (89%) controls. Forty-eight ZNF genes were identified as having hypermethylated CpG sites in CPP.

Conclusion

Methylome profiling of girls at normal and precocious puberty revealed a widespread pattern of DNA hypermethylation, indicating that the pubertal process in humans is associated with specific changes in epigenetically driven regulatory control. Moreover, changes in methylation of several ZNF genes appear to be a distinct epigenetic modification underlying the initiation of human puberty.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0581-1) contains supplementary material, which is available to authorized users.

Central precocious puberty: From genetics to treatment

Central precocious puberty (CPP) results from early activation of the hypothalamic - pituitary -gonadal (HPG) axis and follows the same sequence as normal puberty. While many factors involved in pubertal initiation remain poorly understood, the kisspeptin system is known to play a key role. Currently, mutations in the kisspeptin system, MKRN3, and DLK1 have been identified in sporadic and familial cases of CPP. The diagnosis is based on physical exam findings indicating advancing puberty and on laboratory tests confirming central HPG axis activation. GnRH analogs are the mainstay of treatment and are used with the goal of height preservation. Newer extended release formulations continue to be developed. Currently there is no evidence of long-term complications associated with treatment. However, many areas remain to be explored such as targeted therapies and aspects of clinical management. Further investigation into psychological effects and additional data regarding long-term outcomes, particularly in males, is needed.

Association between MKRN3 and LIN28B polymorphisms and precocious puberty

BACKGROUND

The present study aimed to investigate the association between MKRN3 and LIN28B gene polymorphisms and precocious puberty in Korean boys and girls.

RESULTS

Children 7 to 9 years of age in 2011 to 2012 who were part of the Ewha Birth & Growth Cohort Study were recruited for this study. A total of 103 girls and 70 boys were included in the analyses. Seven girls and 26 boys were identified to have precocious puberty. Among four single nucleotide polymorphisms (SNPs) of MKRN3 and two SNPs of LIN28B examined, three SNPs (rs2239669, rs6576457, and rs12441827) showed significant associations with precocious puberty in additive models in boys but no significance was found in any SNPs in girls. From the logistic regression analysis, boys with TT alleles in rs12441827 had about a four-times greater risk for precocious puberty when compared to C allele carriers (OR = 3.95, 95% CI = 1.27-12.32 in model 1). eQTL analysis revealed that SNPs of statistical significance from our study did not show the variation in expression profiles nor found in the database.

CONCLUSIONS

This study supports the impact of MKRN3 SNP rs12441827 on precocious puberty in Korean boys. The results add a further aspect to genetic association in precocious puberty along with complex interactions of environmental, nutritional and socioeconomic factors.

Two Frameshift Mutations in MKRN3 in Turkish Patients with Familial Central Precocious Puberty

BACKGROUND

Little is known about the genetic causes responsible for idiopathic central precocious puberty (iCPP). More recently, described loss-of-function mutations in the makorin ring finger protein 3 (MKRN3) gene have been demonstrated to be involved in the pathogenesis of familial iCPP.

AIM

The objective of this study was to investigate the potential role of MKRN3 in patients with familial iCPP.

METHODS

We investigated potential sequence variations in the maternal imprinted MKRN3 gene using Next Generation Sequencing (NGS) analysis in 31 participants from 2 families (6 participants were diagnosed with familial iCPP on the basis of clinical and hormonal findings). Six patients diagnosed with familial iCPP and their unaffected first- and second-degree relatives, including their grandparents, were screened for MKRN3 gene variants.

RESULTS

Two heterozygous frameshift mutations (c.441_441delG, p.H148Tfs*23 and c803_803delAT, p.M268Vfs*23) were described in the MKRN3 gene in 2 probands with familial iCPP and in some of their family members. These frameshift mutations create a premature stop codon and result in a truncated protein.

CONCLUSIONS

Our report further expands the MKRN3 gene mutation spectrum in patients with familial iCPP. Screening for potential MKRN3 variants should be performed in patients with familial iCPP as well as in patients with sporadic iCPP.

A new efficient method to monitor precocious puberty nationwide in France

Clinical precocious puberty (PP) is a disease, reputed to be on the increase and suspected to be linked to endocrine disrupting chemicals (EDC) exposure. Population-based epidemiological data are lacking in France and scarce elsewhere. We accessed the feasibility of monitoring PP nationwide in France in this context, using a nationwide existing database, the French National Health Insurance Information System. Here, we present the method we used with a step-by-step approach to build and select the most suitable indicator. We built three indicators reflecting the incidence of idiopathic central precocious puberty (ICPP), the most frequent form of PP, and we compared these indicators according to their strengths and weaknesses with respect to surveillance purposes.

CONCLUSION

Monitoring ICPP in France proved feasible using a Drug reimbursement indicator. Our method is cost efficient and highly relevant in public health surveillance. Our step-by-step approach proved helpful to achieve this project and could be proposed for assessing the feasibility of monitoring health outcomes of interest using existing data bases. What is known: • Precocious puberty (PP) is suspected to be related to EDC exposure and it is believed to be on the increase in France and in others countries. • Very few epidemiologic data on PP are currently available in the world at the national scale. What is new: • This is the first study describing a method to monitor the most frequent form of PP, idiopathic central PP (ICPP) nationwide in a cost-efficient way, using health insurance databases. • This cost-effective method will allow to estimate and monitor the incidence of ICPP in France and to analyze spatial variations at a very precise scale, which will be very useful to examine the role of environmental exposures, especially to EDCs.

Central Precocious Puberty Caused by a Heterozygous Deletion in the MKRN3 Promoter Region

CONTEXT

Loss-of-function mutations in the coding region of MKRN3, a maternally imprinted gene at chromosome 15q11.2, are a common cause of familial central precocious puberty (CPP). Whether MKRN3 alterations in regulatory regions can cause CPP has not been explored to date. We aimed to investigate potential pathogenic variants in the promoter region of MKRN3 in patients with idiopathic CPP.

PATIENTS/METHODS

A cohort of 110 patients with idiopathic CPP was studied. Family history of precocious sexual development was present in 25%. Mutations in the coding region of MKRN3 were excluded in all patients. Genomic DNA was extracted from peripheral blood leukocytes, and 1,100 nucleotides (nt) of the 5'-regulatory region of MKRN3 were amplified and sequenced. Luciferase assays were performed in GT1-7 cells transiently transfected with plasmids containing mutated and wild-type MKRN3 promoter.

RESULTS

We identified a rare heterozygous 4-nt deletion (c.-150_-147delTCAG; -38 to -41 nt upstream to the transcription start site) in the proximal promoter region of MKRN3 in a girl with CPP. In silico analysis predicted that this deletion would lead to the loss of a binding site for a downstream res-ponsive element antagonist modulator (DREAM), a potential transcription factor for MKRN3 and GNRH1 expression. Luciferase assays demonstrated a significant reduction of MKRN3 promoter activity in transfected cells with a c.-150_- 147delTCAG construct plasmid in both homozygous and heterozygous states when compared with cells transfected with the corresponding wild-type MKRN3 promoter region.

CONCLUSION

A rare genetic alteration in the regulatory region of MKRN3 causes CPP.

Identification of differential genomic DNA Methylation in the hypothalamus of pubertal rat using reduced representation Bisulfite sequencing

BACKGROUND

There are many variables affecting the onset of puberty in animals, including genetic, nutritional, and environmental factors. Recent studies suggest that epigenetic regulation, especially DNA methylation, plays a majorrole in the regulation of puberty. However, there have been no reports on DNA methylation of the pubertal genome.

METHODS

We investigated DNA methylation in the female rat hypothalamus at prepuberty and puberty using reduced representation bisulfite sequencing technology. The identified genes and signaling pathways exhibiting changes to DNA methylation in pubertal rats were determined by Gene Ontogeny and Kyoto Encyclopedia of Genes and Genomes analysis.

RESULTS

The distribution of the three types of methylated C bases in promoter and CpG island (CGI) regions in the hypothalamus was as follows: 87.79% CG, 3.05% CHG, 9.16% CHH for promoters, and 88.35% CG, 3.21% CHG, 88.35% CHH for CGI in prepubertal rats; and 90.78% CG, 2.13% CHG, 7.09% CHH for promoters, and 88.59% CG, 88.59% CHG, 8.35% CHH for CGI in pubertal animals. CG showed the highest percentage of methylation, and was the highest methylation state in CGI. Compared to prepubertal hyoyhalamus samples, we identified ten genes with altered methylation in promoter regions in the pubertal hypothalamus samples, and 43 genes with altered methylation in the CGI. Changes in DNA methylation were found in gonadotropin-releasing hormone signaling pathways, and the oocyte meiosis pathway.

CONCLUSION

Our results demonstrate changes in DNA methylation occur in female rats from prepuberty to puberty suggestng DNA methylation may play a crucial role in the regulation of puberty onset. This study provides essential information for future studies on the role of epigenetics in the regulation of puberty.

Mkrn3 functions as a novel ubiquitin E3 ligase to inhibit Nptx1 during puberty initiation

Central precocious puberty (CPP) is attributed to the disorder of some trigger factors those can activate the hypothalamic-pituitary-gonadal axis controlled by GnRH neurons. Many recent studies reveal one of those trigger factors, Makorin ring finger protein 3 (Mkrn3), whose loss-of-function mutations are implicated in CPP. Although Mkrn3 contained zinc Ring finger domain is considered as a putative E3 ubiquitin ligase, its actual function is never reported. Here, our results demonstrated that in mice hypothalamus before and when puberty initiated, Mkrn3 expressed the reversed tendency with Nptx1, which is an important secreted protein for neuron development. Furthermore, our data manifested that Mkrn3 interacted and suppressed Nptx1 activity. And the Ring finger domain of Mkrn3 contained was determined to be essential for binding with Nptx1 for its polyubiquitination during the puberty initiation. Our study shed light on the molecular insights into the function of Mkrn3 in the events of puberty initiation.

[A survey of pubertal development in children born with assisted reproductive technology]

OBJECTIVE

To investigate the status of pubertal development in children born with assisted reproductive technology (ART).

METHODS

A retrospective analysis was performed on the pubertal development data of children born with ART in Peking University Third Hospital from 1994 to 2003 (ART group). The data in the cross-sectional study "Reports on the Physical Fitness and Health Research of Chinese School Students in 2010" were used as a control. The age at menarche and the age at spermarche were compared between the two groups. The status of pubertal development in the overweight and obese children in the ART group was evaluated to investigate the correlation between pubertal development and body mass index (BMI).

RESULTS

A total of 200 children born with ART were enrolled in this study, and 72 of them (41 males and 31 females) completed the survey (response rate=36.0%). In the ART group, the mean age at spermarche and the mean age at menarche were 13.9 years (95%CI: 13.7-14.3 years) and 12.2 years (95%CI: 11.8-12.6 years), respectively. There were no significant differences in the age at spermarche and the age at menarche between the ART and control groups (P>0.05). In the ART group, there were no significant differences in the age at spermarche and the age at menarche between the overweight and obese children and the normal weight children (P>0.05). There were also no significant differences in overweight rate and obesity rate between the children in the ART group and the adolescents in Beijing (P>0.05). In the ART group, there was no significant correlation between the age at spermarche or menarche and BMI (P>0.05).

CONCLUSIONS

No delayed or precocious puberty is observed in children born with ART. This is consistent with the normal control data. And there is no significant correlation between pubertal development and BMI in children born with ART.

The first Japanese case of central precocious puberty with a novel MKRN3 mutation

MKRN3, located on chromosome 15q11.2, encodes makorin ring-finger 3, which is an upstream suppressor of the hypothalamic-pituitary-gonadal axis. Mutation of this gene induces central precocious puberty (CPP). As MKRN3 is maternally imprinted, only the paternal allele is expressed. This is the first report of an 8-year-old Japanese girl with CPP caused by a novel frameshift mutation in MKRN3 (p.Glu229Argfs*3).

Central precocious puberty: revisiting the diagnosis and therapeutic management

Clinical and laboratory diagnosis and treatment of central precocious puberty (CPP) remain challenging due to lack of standardization. The aim of this revision was to address the diagnostic and therapeutic features of CPP in Brazil based on relevant international literature and availability of the existing therapies in the country. The diagnosis of CPP is based mainly on clinical and biochemical parameters, and a period of follow-up is desirable to define the "progressive" form of sexual precocity. This occurs due to the broad spectrum of pubertal development, including isolated premature thelarche, constitutional growth and puberty acceleration, progressive and nonprogressive CPP, and early puberty. Measurement of basal and stimulated LH levels remains challenging, considering that the levels are not always in the pubertal range at baseline, short-acting GnRH is not readily available in Brazil, and the cutoff values differ according to the laboratory assay. When CPP is suspected but basal LH values are at prepubertal range, a stimulation test with short-acting or long-acting monthly GnRH is a diagnostic option. In Brazil, the treatment of choice for progressive CPP and early puberty is a long-acting GnRH analog (GnRHa) administered once a month or every 3 months. In Brazil, formulations of GnRHa (leuprorelin and triptorelin) are available and commonly administered, including 1-month depot leuprorelin 3.75 mg and 7.5 mg, 1-month depot triptorelin 3.75 mg, and 3-month depot leuprorelin 11.25 mg. Monthly or 3-month depot GnRHa are effective and safe to treat CPP. Arch Endocrinol Metab. 2016;60(2):163-72.

Clinical Exome Sequencing Reveals MKRN3 Pathogenic Variants in Familial and Nonfamilial Idiopathic Central Precocious Puberty

BACKGROUND/AIMS

Idiopathic central precocious puberty (ICPP) is the premature activation of the hypothalamic-pituitary-gonadal axis in the absence of organic disease. Up to now, just gain-of-function mutations of KISS1/KISS1R and loss-of-function mutations of the maternally imprinted gene MKRN3 are the known genetic causes of ICPP. Our intention is to evaluate variants present in genes related to the pubertal onset pathway that could act as disease-causing or predisposing variants.

METHODS

We studied the clinical exome of 20 patients diagnosed with ICPP using the Illumina platform. The bioinformatics analysis was performed using 2 different programs, and the variants were filtered according to a list of genes related to the gonadotropin-releasing hormone pathway.

RESULTS

In a "sporadic case," we found a missense variant in MKRN3 NM_005664.3: c.203G>A, causing the protein change NP_005655.1:p.Arg68His, predicted as pathogenic by 2 informatics tools. The proband carrying this variant was diagnosed with ICPP at 7.75 years of age. We did not find any pathogenic variants in KISS1, KISS1R, LIN28, GNRH, GNRHR, TACR3, and TAC3.

CONCLUSION

MKRN3 is the most frequent genetic cause of familial ICPP, so it is wise to screen for MKRN3 mutations in all patients with familial ICPP and in patients with an unclear paternal pubertal history.

Luteinizing Hormone Secretion during Gonadotropin-Releasing Hormone Stimulation Tests in Obese Girls with Central Precocious Puberty

OBJECTIVE

Girls with precocious puberty have high luteinizing hormone (LH) levels and advanced bone age. Obese children enter puberty at earlier ages than do non-obese children. We analyzed the effects of obesity on LH secretion during gonadotropin-releasing hormone (GnRH) tests in girls with precocious puberty.

METHODS

A total of 981 subjects with idiopathic precocious puberty who had undergone a GnRH stimulation testing between 2008 and 2014 were included in the study. Subjects were divided into three groups based on body mass index (BMI). Auxological data and gonadotropin levels after the GnRH stimulation test were compared.

RESULTS

In Tanner stage 2 girls, peak stimulated LH levels on GnRH test were 11.9±7.5, 10.4±6.4, and 9.1±6.1 IU/L among normal-weight, overweight, and obese subjects, respectively (p=0.035 for all comparisons). In Tanner stage 3 girls, peak stimulated LH levels were 14.9±10.9, 12.8±7.9, and 9.6±6.0 IU/L, respectively (p=0.022 for all comparisons). However, in Tanner stage 4 girls, peak stimulated LH levels were not significantly different among normal, overweight, and obese children. On multivariate analysis, BMI standard deviation score was significantly and negatively associated with peak LH (β=-1.178, p=0.001).

CONCLUSION

In girls with central precocious puberty, increased BMI was associated with slightly lower peak stimulated LH levels at early pubertal stages (Tanner stages 2 and 3). This association was not valid in Tanner stage 4 girls.

Assessment of Estradiol Response after Depot Triptorelin Administration in Girls with Central Precocious Puberty

BACKGROUND

Estradiol at baseline or after a classical gonadotropin-releasing hormone test did not reflect ovarian steroidogenesis in central precocious puberty (CPP) girls.

AIMS

To evaluate estradiol response to depot triptorelin, both at start and during therapy to determine how active ovarian steroidogenesis is at pubertal stage and under therapy.

METHODS

A prospective study was performed in 43 CPP girls. Serum luteinizing hormone and follicle-stimulating hormone at 3 h (LH-3h, FSH-3h) and estradiol at 24 h (E2-24h) after injection of depot triptorelin 3.75 mg were measured, at first dose and at 3, 6, 12, 18 and 24 months of treatment.

RESULTS

E2-24h after depot triptorelin was >100 pg/ml after the first dose. Estradiol response (E2-24h) fell to levels <14 pg/ml in 78 out of 82 follow-up visits along 2 years of therapy. Concomitantly, LH-3h and FSH-3h were <4.0 and <6.3 IU/l, respectively. In 4 patients with inadequate treatment, E2-24h, LH-3h and FSH-3h rose to pubertal values similar to those observed at first dose.

CONCLUSION

Estradiol (<14 pg/ml) assessment 24 h after depot triptorelin administration is a reliable and simple manner to confirm ovarian suppression in CPP girls during treatment.

Control of puberty onset and fertility by gonadotropin-releasing hormone neurons

The gonadotropin-releasing hormone (GnRH) neuronal network generates pulse and surge modes of gonadotropin secretion critical for puberty and fertility. The arcuate nucleus kisspeptin neurons that innervate the projections of GnRH neurons in and around their neurosecretory zone are key components of the pulse generator in all mammals. By contrast, kisspeptin neurons located in the preoptic area project to GnRH neuron cell bodies and proximal dendrites and are involved in surge generation in female rodents (and possibly other species). The hypothalamic-pituitary-gonadal axis develops embryonically but, apart from short periods of activation immediately after birth, remains suppressed through a combination of gonadal and non-gonadal mechanisms. At puberty onset, the pulse generator reactivates, probably owing to progressive stimulatory influences on GnRH neurons from glial and neurotransmitter signalling, and the re-emergence of stimulatory arcuate kisspeptin input. In females, the development of pulsatile gonadotropin secretion enables final maturation of the surge generator that ultimately triggers the first ovulation. Representation of the GnRH neuronal network as a series of interlocking functional modules could help conceptualization of its functioning in different species. Insights into pulse and surge generation are expected to aid development of therapeutic strategies ameliorating pubertal disorders and infertility in the clinic.

High Frequency of MKRN3 Mutations in Male Central Precocious Puberty Previously Classified as Idiopathic

BACKGROUND/AIMS

Recently, loss-of-function mutations in the MKRN3 gene have been implicated in the etiology of familial central precocious puberty (CPP) in both sexes. We aimed to analyze the frequency of MKRN3 mutations in boys with CPP and to compare the clinical and hormonal features of boys with and without MKRN3 mutations.

METHODS

This was a retrospective review of clinical, hormonal and genetic features of 20 male patients with idiopathic CPP evaluated at an academic medical center. The entire coding regions of MKRN3, KISS1 and KISS1R genes were sequenced.

RESULTS

We studied 20 boys from 17 families with CPP. All of them had normal brain magnetic resonance imaging. Eight boys from 5 families harbored four distinct heterozygous MKRN3 mutations predicted to be deleterious for protein function, p.Ala162Glyfs*14, p.Arg213Glyfs*73, p.Arg328Cys and p.Arg365Ser. One boy carried a previously described KISS1-activating mutation (p.Pro74Ser). The frequency of MKRN3 mutations among these boys with idiopathic CPP was significantly higher than previously reported female data (40 vs. 6.4%, respectively, p < 0.001). Boys with MKRN3 mutations had typical clinical and hormonal features of CPP. Notably, they had later pubertal onset than boys without MKRN3 abnormalities (median age 8.2 vs. 7.0 years, respectively, p = 0.033).

CONCLUSION

We demonstrated a high frequency of MKRN3 mutations in boys with CPP, previously classified as idiopathic, suggesting the importance of genetic analysis in this group. The boys with CPP due to MKRN3 mutations had classical features of CPP, but with puberty initiation at a borderline age.

Fatness rather than leptin sensitivity determines the timing of puberty in female mice

Leptin is a permissive factor for the onset of puberty. However, changes in adiposity frequently influence leptin sensitivity. Thus, the objective of the present study was to investigate how changes in body weight, fatness, leptin levels and leptin sensitivity interact to control the timing of puberty in female mice. Pre-pubertal obesity, induced by raising C57BL/6 mice in small litters, led to an early puberty onset. Inactivation of Socs3 gene in the brain or exclusively in leptin receptor-expressing cells reduced the body weight and leptin levels at pubertal onset, and increased leptin sensitivity. Notably, these female mice exhibited significant delays in vaginal opening, first estrus and onset of estrus cyclicity. In conclusion, our findings suggest that increased leptin sensitivity did not play an important role in favoring pubertal onset in female mice. Rather, changes in pubertal body weight, fatness and/or leptin levels were more important in influencing the timing of puberty.

MANAGEMENT OF ENDOCRINE DISEASE: Long-term outcomes of the treatment of central precocious puberty

GnRH analogues (GnRHa) are the treatment of choice for central precocious puberty (CPP), with the main objective to recover the height potential compromised by the premature fusion of growth cartilages. The aim of this review was to analyze long-term effects of GnRHa on height, body weight, reproductive function, and bone mineral density (BMD) in patients with CPP, as well as the potential predictors of outcome. Because randomized controlled trials on the effectiveness and long-term outcomes of treatment are not available, only qualified conclusions about the efficacy of interventions can be drawn. GnRHa treatment appears to improve adult height in girls with CPP, especially if diagnosed before the age of 6, whereas a real benefit in terms of adult height is still controversial in patients with the onset of puberty between 6 and 8 years of age. No height benefit was shown in patients treated after 8 years. Gonadal function is promptly restored in girls after cessation of treatment, and reproductive potential appears normal in young adulthood. Data are conflicting on the long-term risk of polycystic ovarian syndrome in both treated and untreated women. Fat mass is increased at the start of treatment but normalizes thereafter, and GnRHa itself does not seem to have any long-term effect on BMI. Similarly, analogue treatment does not appear to have a negative impact on BMD. Owing to the paucity of data available, no conclusions can be drawn on the repercussions of CPP and/or its treatment on the timing of menopause and on the health of the offspring.

Causes, diagnosis, and treatment of central precocious puberty

Central precocious puberty results from the premature activation of the hypothalamic-pituitary-gonadal axis. It mimics physiological pubertal development, although at an inappropriate chronological age (before 8 years in girls and 9 years in boys). It can be attributable to cerebral congenital malformations or acquired insults, but the cause in most cases in girls remains unknown. MKRN3 gene defects have been identified in familial disease, with important basic and clinical results. Indeed, genetic analysis of this gene should be included in the routine clinical investigation of familial and idiopathic cases of central precocious puberty. Gonadotropin-releasing hormone agonists are the gold-standard treatment. The assessment and management of this disease remain challenging for paediatric endocrinologists. In this Series paper, we describe current challenges involving the precise diagnosis and adequate treatment of this disorder.

The Changes of Serum Leptin and Kisspeptin Levels in Chinese Children and Adolescents in Different Pubertal Stages

The aim of the study is to investigate the changes of serum leptin and kisspeptin levels in children and adolescents with different pubertal stages and nutritional states. A total of 647 Chinese children and adolescents were recruited, and serum estradiol, testosterone, pituitary gonadotropins, leptin, and kisspeptin levels were measured. The results showed that serum leptin levels of boys in T2 stage were the highest among the five stages, while they showed a gradual increase from T1 to T5 stage in girls and reached the highest in T5 stage (P < 0.05). Conversely, serum kisspeptin levels of boys were higher in T4 and T5 stages than those in T1 stage, while its levels of girls were the highest in T2 stage, 21.4% higher than those in T1 stage (P < 0.05). Both leptin and kisspeptin levels were positively correlated with BMI, WC, and weight in all boys and girls (all P < 0.05). In conclusion, kisspeptin levels were firstly found to be notably changed in pubertal stages and nutritional status in Chinese children and adolescents with a significant sexual dimorphism. Obese/overweight girls had higher kisspeptin levels, and there was a positive correlation between kisspeptin and FSH and LH and obesity-related parameters in all boys and girls.

In silico analysis of a novel MKRN3 missense mutation in familial central precocious puberty

BACKGROUND

The onset of puberty is influenced by the interplay of stimulating and restraining factors, many of which have a genetic origin. Premature activation of the GnRH secretion in central precocious puberty (CPP) may arise either from gain-of-function mutations of the KISS1 and KISS1R genes or from loss-of-function manner mutations of the MKRN3 gene leading to MKRN3 deficiency.

OBJECTIVE

To explore the genetic causes responsible for CPP and the potential role of the RING finger protein 3 (MKRN3) gene.

DESIGN AND PATIENTS

We investigated potential sequence variations in the intronless MKRN3 gene by Sanger sequencing of the entire 507 amino acid coding region of exon 1 in a family with two affected girls presented with CPP at the age of 6 and 5·7 years, respectively.

RESULTS

A novel heterozygous g.Gly312Asp missense mutation in the MKRN3 gene was identified in these siblings. The imprinted MKRN3 missense mutation was also identified as expected in the unaffected father and followed as expected an imprinted mode of inheritance. In silico analysis of the altered missense variant using the computational algorithms Polyphen2, SIFT and Mutation Taster predicted a damage and pathogenic alteration causing CPP. The pathogenicity of the alteration at the protein level via an in silico structural model is also explored.

CONCLUSION

A novel mutation in the MKRN3 gene in two sisters with CPP was identified, supporting the fundamental role of this gene in the suppression of the hypothalamic GnRH neurons.

A missense mutation in MKRN3 in a Danish girl with central precocious puberty and her brother with early puberty

BACKGROUND

Idiopathic central precocious puberty (ICPP) results from the premature reactivation of the hypothalamic-pituitary-gonadal axis leading to development of secondary sexual characteristics prior to 8 y in girls or 9 y in boys. Since the initial discovery of mutations in the maternally imprinted MKRN3 gene in 2013, several case reports have described mutations in this gene in ICPP patients from different populations, highlighting the importance of MKRN3 as a regulator of pubertal onset.

METHODS

We screened 29 Danish girls with ICPP for mutations in MKRN3. Expression of MKRN3 in human hypothalamic complementary DNA (cDNA) was investigated by PCR.

RESULTS

One paternally inherited rare variant, c.1034G>A (p.Arg345His), was identified in one girl with ICPP and in her brother with early puberty. The variant is predicted to be deleterious by three different in silico prediction programs. Expression of MKRN3 was confirmed in adult human hypothalamus.

CONCLUSION

Our results are in line with previous studies in which paternally inherited MKRN3 mutations have been found both in males and in females with ICPP or early puberty. Our report further expands the set of MKRN3 mutations identified in ICPP patients across diverse populations, thus supporting the major regulatory function of MKRN3 in pubertal onset.

60 YEARS OF NEUROENDOCRINOLOGY: MEMOIR: Harris' neuroendocrine revolution: of portal vessels and self-priming

Geoffrey Harris, while still a medical student at Cambridge, was the first researcher (1937) to provide experimental proof for the then tentative view that the anterior pituitary gland was controlled by the CNS. The elegant studies carried out by Harris in the 1940s and early 1950s, alone and in collaboration with John Green and Dora Jacobsohn, established that this control was mediated by a neurohumoral mechanism that involved the transport by hypophysial portal vessel blood of chemical substances from the hypothalamus to the anterior pituitary gland. The neurohumoral control of anterior pituitary secretion was proved by the isolation and characterisation of the 'chemical substances' (mainly neuropeptides) and the finding that these substances were released into hypophysial portal blood in a manner consistent with their physiological functions. The new discipline of neuroendocrinology - the way that the brain controls endocrine glands and vice versa - revolutionised the treatment of endocrine disorders such as growth and pubertal abnormalities, infertility and hormone-dependent tumours, and it underpins our understanding of the sexual differentiation of the brain and key aspects of behaviour and mental disorder. Neuroendocrine principles are illustrated in this Thematic Review by way of Harris' major interest: hypothalamic-pituitary-gonadal control. Attention is focussed on the measurement of GnRH in hypophysial portal blood and the role played by the self-priming effect of GnRH in promoting the onset of puberty and enabling the oestrogen-induced surge or pulses of GnRH to trigger the ovulatory gonadotrophin surge in humans and other spontaneously ovulating mammals.