Familial central precocious puberty due to DLK1 deficiency: novel genetic findings and relevance of serum DLK1 levels.

BACKGROUND: Several rare loss-of-function mutations of delta-like noncanonical notch ligand 1 (DLK1) have been described in non-syndromic children with familial central precocious puberty (CPP). OBJECTIVE: We investigated genetic abnormalities of DLK1 gene in a French cohort of children with idiopathic CPP. Additionally, we explored the pattern of DLK1 serum levels in patients with CPP and in healthy children at puberty, as well as in wild-type female mice. PATIENTS AND METHODS: Genomic DNA was obtained from 121 French index cases with CPP. Automated sequencing of the coding region of the DLK1 gene was performed in all cases. Serum DLK1 levels were measured by enzyme linked immunosorbent assay (ELISA) in 209 individuals, including 191 with normal pubertal development and in female mice during postnatal pubertal maturation. RESULTS: We identified 2 rare pathogenic DLK1 allelic variants: A stop gain variant (c.372C>A; p.Cys124X) and a start loss variant (c.2T>G; p.Met1?, or p.0) in 2 French girls with CPP. Mean serum DLK1 levels were similar between healthy children and idiopathic CPP children. In healthy individuals, DLK1 levels correlated with pubertal stage: In girls, DLK1 decreased between Tanner stages III and V, whereas in boys, DLK1 decreased between Tanner stages II and V (P = .008 and .016, respectively). Serum levels of Dlk1 also decreased in wild-type female mice. CONCLUSIONS: Novel loss-of-function mutations in DLK1 gene were identified in 2 French girls with CPP. Additionally, we demonstrated a pattern of dynamic changes in circulating DLK1 serum levels in humans and mice during pubertal stages, reinforcing the role of this factor in pubertal timing.

Rare variants in the MECP2 gene in girls with central precocious puberty: a translational cohort study.

BACKGROUND: Identification of genetic causes of central precocious puberty have revealed epigenetic mechanisms as regulators of human pubertal timing. MECP2, an X-linked gene, encodes a chromatin-associated protein with a role in gene transcription. MECP2 loss-of-function mutations usually cause Rett syndrome, a severe neurodevelopmental disorder. Early pubertal development has been shown in several patients with Rett syndrome. The aim of this study was to explore whether MECP2 variants are associated with an idiopathic central precocious puberty phenotype. METHODS: In this translational cohort study, participants were recruited from seven tertiary centres from five countries (Brazil, Spain, France, the USA, and the UK). Patients with idiopathic central precocious puberty were investigated for rare potentially damaging variants in the MECP2 gene, to assess whether MECP2 might contribute to the cause of central precocious puberty. Inclusion criteria were the development of progressive pubertal signs (Tanner stage 2) before the age of 8 years in girls and 9 years in boys and basal or GnRH-stimulated LH pubertal concentrations. Exclusion criteria were the diagnosis of peripheral precocious puberty and the presence of any recognised cause of central precocious puberty (CNS lesions, known monogenic causes, genetic syndromes, or early exposure to sex steroids). All patients included were followed up at the outpatient clinics of participating academic centres. We used high-throughput sequencing in 133 patients and Sanger sequencing of MECP2 in an additional 271 patients. Hypothalamic expression of Mecp2 and colocalisation with GnRH neurons were determined in mice to show expression of Mecp2 in key nuclei related to pubertal timing regulation. FINDINGS: Between Jun 15, 2020, and Jun 15, 2022, 404 patients with idiopathic central precocious puberty (383 [95%] girls and 21 [5%] boys; 261 [65%] sporadic cases and 143 [35%] familial cases from 134 unrelated families) were enrolled and assessed. We identified three rare heterozygous likely damaging coding variants in MECP2 in five girls: a de novo missense variant (Arg97Cys) in two monozygotic twin sisters with central precocious puberty and microcephaly; a de novo missense variant (Ser176Arg) in one girl with sporadic central precocious puberty, obesity, and autism; and an insertion (Ala6_Ala8dup) in two unrelated girls with sporadic central precocious puberty. Additionally, we identified one rare heterozygous 3'UTR MECP2 insertion (36_37insT) in two unrelated girls with sporadic central precocious puberty. None of them manifested Rett syndrome. Mecp2 protein colocalised with GnRH expression in hypothalamic nuclei responsible for GnRH regulation in mice. INTERPRETATION: We identified rare MECP2 variants in girls with central precocious puberty, with or without mild neurodevelopmental abnormalities. MECP2 might have a role in the hypothalamic control of human pubertal timing, adding to the evidence of involvement of epigenetic and genetic mechanisms in this crucial biological process. FUNDING: Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico, and the Wellcome Trust.

Clinical and Genetic Characterization of Familial Central Precocious Puberty.

CONTEXT: Central precocious puberty (CPP) can have a familial form in approximately one-quarter of the children. The recognition of this inherited condition increased after the identification of autosomal dominant CPP with paternal transmission caused by mutations in the MKRN3 and DLK1 genes. OBJECTIVE: We aimed to characterize the inheritance and estimate the prevalence of familial CPP in a large multiethnic cohort; to compare clinical and hormonal features, as well as treatment response to GnRH analogs (GnRHa), in children with distinct modes of transmission; and to investigate the genetic basis of familial CPP. METHODS: We retrospectively studied 586 children with a diagnosis of CPP. Patients with familial CPP (n = 276) were selected for clinical and genetic analysis. Data from previous studies were grouped, encompassing sequencing of MKRN3 and DLK1 genes in 204 patients. Large-scale parallel sequencing was performed in 48 individuals from 34 families. RESULTS: The prevalence of familial CPP was estimated at 22%, with a similar frequency of maternal and paternal transmission. Pedigree analyses of families with maternal transmission suggested an autosomal dominant inheritance. Clinical and hormonal features, as well as treatment response to GnRHa, were similar among patients with different forms of transmission of familial CPP. MKRN3 loss-of-function mutations were the most prevalent cause of familial CPP, followed by DLK1 loss-of-function mutations, affecting, respectively, 22% and 4% of the studied families; both affected exclusively families with paternal transmission. Rare variants of uncertain significance were identified in CPP families with maternal transmission. CONCLUSION: We demonstrated a similar prevalence of familial CPP with maternal and paternal transmission. MKRN3 and DLK1 loss-of-function mutations were the major causes of familial CPP with paternal transmission.

Anthropometric, metabolic, and reproductive outcomes of patients with central precocious puberty treated with leuprorelin acetate 3-month depot (11.25 mg).

OBJECTIVES: Longer-acting gonadotropin-releasing hormone analogs (GnRHa) have been widely used for central precocious puberty (CPP) treatment. However, the follow-up of patients after this treatment are still scarce. Our aim was to describe anthropometric, metabolic, and reproductive follow-up of CPP patients after treatment with leuprorelin acetate 3-month depot (11.25 mg). METHODS: Twenty-two female patients with idiopathic CPP were treated with leuprorelin acetate 3-month depot (11.25 mg). Their medical records were retrospectively evaluated regarding clinical, hormonal, and imaging aspects before, during, and after GnRHa treatment until adult height (AH). RESULTS: At the diagnosis of CPP, the mean chronological age (CA) was 8.2 ± 1.13 year, and mean bone age (BA) was 10.4 ± 1.4 year. Mean height SDS at the start and the end of GnRHa treatment was 1.6 ± 0.8 and 1.3 ± 0.9, respectively. The mean duration of GnRHa treatment was 2.8 ± 0.8 year. Mean predicted adult heights (PAH) at the start and the end of GnRH treatment was 153.2 ± 8.6 and 164.4 ± 7.3 cm, respectively (p<0.05). The mean AH was 163.2 ± 6.2 cm (mean SDS: 0.1 ± 1). All patients were within their target height (TH) range. There was a decrease in the percentage of overweight and obesity from the diagnosis until AH (39-19% p>0.05). At the AH, the insulin resistance and high LDL levels were identified in 3/17 patients (17.6%) and 2/21 patients (9.5%), respectively. The mean CA of menarche was 12.2 ± 0.5 years. At the AH, PCOS was diagnosed in one patient (4.8%). CONCLUSIONS: Long-term anthropometric, metabolic, and reproductive follow-up of patients with CPP treated with longer-acting GnRHa revealed effectivity, safety, and favorable outcomes.

Distócia de ombro / Shoulder dystocia

A Distócia de Ombro é definida, de acordo com os Colégios Americano e Britânico de Obstetrícia e Ginecologia, como parto que necessita de manobras obstétricas adicionais, após falência da tração da cabeça fetal para liberar os ombros. Apesar de sua baixa incidência, é uma complicação com importante morbidade para o recém nascido e que pode levar a intercorrências maternas, sendo entretanto passível de ser evitada. Esse artigo de revisão se propõe a sumarizar a epidemiologia, fisiopatologia, conduta e complicações, enfocando os fatores de risco e as manobras mais utilizadas, dada a importância de ambos na prevenção dessa complicação. (AU)

The Shoulder Dystocia is defined, according to British and American Colleges of Obstetrics and Gynecology, as delivery which requires additional obstetric maneuvers after failure of traction of the fetal head to release the shoulders. Despite its low incidence, it is a complication with significant morbidity for the newborn and wich can lead to maternal complications. Despite of this, is able to be avoided. This review aims to summarize the epidemiology, pathophysiology, management and complications, focusing on risk factors and the most commonly used maneuvers, due to the importance of both in preventing this complication. (AU)