ANA CLAUDIA LATRONICO XAVIER
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Clínica Médica, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
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conferenceObject Genetic evaluation in children with self-limited pubertal delay discloses new candidate genes(2023) REZENDE, Raissa; SCHAFER, Evan; KAISINGER, Lena; HE, Wen; ANDRADE, Nathalia; DANTAS, Naiara; CELLIN, Laurana; QUEDAS, Elisangela; PERRY, John; HOWARD, Sasha; LATRONICO, Ana Claudia; CHAN, Yee-Ming; JORGE, AlexanderconferenceObject Several new candidate genes for self-limited delayed puberty revealed by whole exome sequencing(2023) REZENDE, Raissa; SCHAFER, Evan; KAISINGER, Lena; DANTAS, Naiara; ANDRADE, Nathalia; CELLIN, Laurana; QUEDAS, Elisangela; HE, Wen; PERRY, John; XAVIER, Ana Claudia Latronico; HOWARD, Sasha; CHAN, Yee-Ming; JORGE, Alexander- Molecular basis of normal and pathological puberty: from basic mechanisms to clinical implications(2023) ARGENTE, Jesus; DUNKEL, Leo; KAISER, Ursula B.; LATRONICO, Ana C.; LOMNICZI, Alejandro; SORIANO-GUILLEN, Leandro; TENA-SEMPERE, ManuelPuberty is a major maturational event; its mechanisms and timing are driven by genetic determinants, but also controlled by endogenous and environmental cues. Substantial progress towards elucidation of the neuroendocrine networks governing puberty has taken place. However, key aspects of the mechanisms responsible for the precise timing of puberty and its alterations have only recently begun to be deciphered, propelled by epidemiological data suggesting that pubertal timing is changing in humans, via mechanisms that are not yet understood. By integrating basic and clinical data, we provide a comprehensive overview of current advances on the physiological basis of puberty, with a particular focus on the roles of kisspeptins and other central transmitters, the underlying molecular and endocrine mechanisms, and the pathways involved in pubertal modulation by nutritional and metabolic cues. Additionally, we have summarised molecular features of precocious and delayed puberty in both sexes, as revealed by clinical and genetic studies. This Review is a synoptic up-to-date view of how puberty is controlled and of the pathogenesis of major pubertal alterations, from both a clinical and translational perspective. We also highlight unsolved challenges that will seemingly concentrate future research efforts in this active domain of endocrinology.
- Rare variants in the MECP2 gene in girls with central precocious puberty: a translational cohort study(2023) CANTON, Ana P. M.; TINANO, Flavia R.; GUASTI, Leonardo; MONTENEGRO, Luciana R.; RYAN, Fiona; SHEARS, Deborah; MELO, Maria Edna de; GOMES, Larissa G.; PIANA, Mariana P.; BRAUNER, Raja; ESPINO-AGUILAR, Rafael; ESCRIBANO-MUNOZ, Arancha; PAGANONI, Alyssa; READ, Jordan E.; KORBONITS, Marta; SERAPHIM, Carlos E.; COSTA, Silvia S.; KREPISCHI, Ana Cristina; JORGE, Alexander A. L.; DAVID, Alessia; KAISINGER, Lena R.; ONG, Ken K.; PERRY, John R. B.; ABREU, Ana Paula; KAISER, Ursula B.; ARGENTE, Jesus; MENDONCA, Berenice B.; BRITO, Vinicius N.; HOWARD, Sasha R.; LATRONICO, Ana ClaudiaBackground 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 & PRIME;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.
- Prevalence of Deleterious Variants in MC3R in Patients With Constitutional Delay of Growth and Puberty(2023) DUCKETT, Katie; WILLIAMSON, Alice; KINCAID, John W. R.; RAINBOW, Kara; CORBIN, Laura J.; MARTIN, Hilary C.; EBERHARDT, Ruth Y.; HUANG, Qin Qin; HURLES, Matthew E.; HE, Wen; BRAUNER, Raja; DELANEY, Angela; DUNKEL, Leo; GRINSPON, Romina P.; HALL, Janet E.; HIRSCHHORN, Joel N.; HOWARD, Sasha R.; LATRONICO, Ana C.; JORGE, Alexander A. L.; MCELREAVEY, Ken; MERICQ, Veronica; MERINO, Paulina M.; PALMERT, Mark R.; PLUMMER, Lacey; REY, Rodolfo A.; REZENDE, Raissa C.; SEMINARA, Stephanie B.; SALNIKOV, Kathryn; BANERJEE, Indraneel; LAM, Brian Y. H.; PERRY, John R. B.; TIMPSON, Nicholas J.; CLAYTON, Peter; CHAN, Yee-Ming; ONG, Ken K.; O'RAHILLY, StephenContext The melanocortin 3 receptor (MC3R) has recently emerged as a critical regulator of pubertal timing, linear growth, and the acquisition of lean mass in humans and mice. In population-based studies, heterozygous carriers of deleterious variants in MC3R report a later onset of puberty than noncarriers. However, the frequency of such variants in patients who present with clinical disorders of pubertal development is currently unknown. Objective This work aimed to determine whether deleterious MC3R variants are more frequently found in patients clinically presenting with constitutional delay of growth and puberty (CDGP) or normosmic idiopathic hypogonadotropic hypogonadism (nIHH). Methods We examined the sequence of MC3R in 362 adolescents with a clinical diagnosis of CDGP and 657 patients with nIHH, experimentally characterized the signaling properties of all nonsynonymous variants found and compared their frequency to that in 5774 controls from a population-based cohort. Additionally, we established the relative frequency of predicted deleterious variants in individuals with self-reported delayed vs normally timed menarche/voice-breaking in the UK Biobank cohort. Results MC3R loss-of-function variants were infrequent but overrepresented in patients with CDGP (8/362 [2.2%]; OR = 4.17; P = .001). There was no strong evidence of overrepresentation in patients with nIHH (4/657 [0.6%]; OR = 1.15; P = .779). In 246 328 women from the UK Biobank, predicted deleterious variants were more frequently found in those self-reporting delayed (aged & GE;16 years) vs normal age at menarche (OR = 1.66; P = 3.90E-07). Conclusion We have found evidence that functionally damaging variants in MC3R are overrepresented in individuals with CDGP but are not a common cause of this phenotype.