VINICIUS NAHIME DE BRITO
Projetos de Pesquisa
Unidades Organizacionais
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
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conferenceObject X-Linked Central Precocious Puberty Associated with MECP2 defects(2022) CANTON, Ana; TINANO, Flavia; GUASTI, Leonardo; MONTENEGRO, Luciana; RYAN, Fiona; SHEARS, Deborah; MELO, Maria Edna; GOMES, Larissa; PIANA, Mariana; BRAUNER, Raja; ESPINO, Rafael; ESCRIBANO-MUNOZ, Arancha; PAGANONI, Alyssa; KORBONITS, Marta; SERAPHIM, Carlos Eduardo; FARIA, Aline; COSTA, Silvia; KREPISCHI, Ana Cristina; JORGE, Alexander; DAVID, Alessia; ARGENTE, Jesus; MENDONCA, Berenice; BRITO, Vinicius; HOWARD, Sasha; LATRONICO, Ana Claudia- Mutational analysis of TAC3 and TACR3 genes in patients with idiopathic central pubertal disorders(2012) TUSSET, Cintia; NOEL, Sekoni D.; TRARBACH, Ericka B.; SILVEIRA, Leticia F. G.; JORGE, Alexander A. L.; BRITO, Vinicius N.; CUKIER, Priscila; SEMINARA, Stephanie B.; MENDONCA, Berenice B. de; KAISER, Ursula B.; LATRONICO, Ana ClaudiaObjective: To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. Subjects and methods: Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH), and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. Results: We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C > T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L, and p.W275* variants were identified in three unrelated males with normosmic IHH. Conclusion: Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype.
- The Congenital and Acquired Mechanisms Implicated in the Etiology of Central Precocious Puberty(2023) BRITO, Vinicius N.; CANTON, Ana P. M.; SERAPHIM, Carlos Eduardo; ABREU, Ana Paula; MACEDO, Delanie B.; MENDONCA, Berenice B.; KAISER, Ursula B.; ARGENTE, Jesus; LATRONICO, Ana ClaudiaThe etiology of central precocious puberty (CPP) is multiple and heterogeneous, including congenital and acquired causes that can be associated with structural or functional brain alterations. All causes of CPP culminate in the premature pulsatile secretion of hypothalamic GnRH and, consequently, in the premature reactivation of hypothalamic-pituitary-gonadal axis. The activation of excitatory factors or suppression of inhibitory factors during childhood represent the 2 major mechanisms of CPP, revealing a delicate balance of these opposing neuronal pathways. Hypothalamic hamartoma (HH) is the most well-known congenital cause of CPP with central nervous system abnormalities. Several mechanisms by which hamartoma causes CPP have been proposed, including an anatomical connection to the anterior hypothalamus, autonomous neuroendocrine activity in GnRH neurons, trophic factors secreted by HH, and mechanical pressure applied to the hypothalamus. The importance of genetic and/or epigenetic factors in the underlying mechanisms of CPP has grown significantly in the last decade, as demonstrated by the evidence of genetic abnormalities in hypothalamic structural lesions (eg, hamartomas, gliomas), syndromic disorders associated with CPP (Temple, Prader-Willi, Silver-Russell, and Rett syndromes), and isolated CPP from monogenic defects (MKRN3 and DLK1 loss-of-function mutations). Genetic and epigenetic discoveries involving the etiology of CPP have had influence on the diagnosis and familial counseling providing bases for potential prevention of premature sexual development and new treatment targets in the future. Global preventive actions inducing healthy lifestyle habits and less exposure to endocrine-disrupting chemicals during the lifespan are desirable because they are potentially associated with CPP.
conferenceObject Apparently Sporadic Central Precocious Puberty Is Caused By Paternally Inherited Mutations in the Imprinted MKRN3 Gene(2014) ABREU, Ana Paula; MACEDO, Delanie B.; REIS, Ana Claudia Silva; MONTENEGRO, Luciana Ribeiro; DAUBER, Andrew; BENEDUZZI, Diane; CULIER, Priscilla; SILVEIRA, Leticia Gontijo; TELES, Milena Gurgel; CARROLL, Rona S.; GUERRA, Gil; GUARAGNA FILHO, Guilherme; GUCEV, Zoran Spasico; ARNHOLD, Ivo J. P.; CASTRO, Margaret; MOREIRA, Ayrton Custodio; MARTINELLI, Carlos Eduardo; HIRSCHHORN, Joel N.; MENDONASA, Berenice Bilharinho; BRITO, Vinicius N.; ANTONINI, Sonir Roberto; KAISER, Ursula B.; LATRONICO, Ana Claudia- High Frequency of MKRN3 Mutations in Male Central Precocious Puberty Previously Classified as Idiopathic(2017) BESSA, Danielle S.; MACEDO, Delanie B.; BRITO, Vinicius N.; FRANCA, Monica M.; MONTENEGRO, Luciana R.; CUNHA-SILVA, Marina; SILVEIRA, Leticia G.; HUMMEL, Tiago; BERGADA, Ignacio; BRASLAVSKY, Debora; ABREU, Ana Paula; DAUBER, Andrew; MENDONCA, Berenice B.; KAISER, Ursula B.; LATRONICO, Ana ClaudiaBackground/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. (C) 2016 S. Karger AG, Basel
conferenceObject Clinical and Genetic Features of Central Precocious Puberty Associated with Complex Phenotypes(2018) CANTON, Ana; BRITO, Vinicius; MONTENEGRO, Luciana; RAMOS, Carolina; MACEDO, Delanie; BESSA, Danielle; CUNHA, Marina; JORGE, Alexander; MENDONCA, Berenice; LATRONICO, Ana ClaudiabookPart Puberdade precoce central(2021) BRITO, Vinícius Nahime de; LATRONICO, Ana Claudia; MENDONçA, Berenice Bilharinho- Methylome profiling of healthy and central precocious puberty girls(2018) BESSA, Danielle S.; MASCHIETTO, Mariana; AYLWIN, Carlos Francisco; CANTON, Ana P. M.; BRITO, Vinicius N.; MACEDO, Delanie B.; CUNHA-SILVA, Marina; PALHARES, Heloisa M. C.; RESENDE, Elisabete A. M. R. de; BORGES, Maria de Fatima; MENDONCA, Berenice B.; NETCHINE, Irene; KREPISCHI, Ana C. V.; LOMNICZI, Alejandro; OJEDA, Sergio R.; LATRONICO, Ana ClaudiaBackgroundRecent 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.ResultsAnalyzing 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.ConclusionMethylome 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.
- Applicability of a novel mathematical model for the prediction of adult height and age at menarche in girls with idiopathic central precocious puberty(2018) LOPES, Mateus Cavarzan; RAMOS, Carolina Oliveira; LATRONICO, Ana Claudia; MENDONCA, Berenice B.; BRITO, Vinicius N.OBJECTIVES: Unfavorable predicted adult height and psychosocial inadequacy represent parameters used to guide therapeutic intervention in girls with central precocious puberty. Gonadotropin-releasing hormone analog is the first-line treatment. The aim of this study was to compare two methods used to predict adult height and assess a validated tool for predicting the age at menarche in girls with central precocious puberty. METHODS: The predicted adult height of 48 girls with central precocious puberty was calculated at diagnosis using the Bayley-Pinneau method based on average and advanced bone age tables and compared with the predicted adult height calculated using a mathematical model. In addition, the age at spontaneous menarche was predicted using the new formulae. After Gonadotropin-releasing hormone analog treatment, the predicted adult height was calculated using only the Bayley-Pinneau tables. RESULTS: The achieved adult height was within the target height range in all treated girls with central precocious puberty. At diagnosis, the predicted adult height using the Bayley-Pinneau tables was lower than that using the mathematical model. After the Gonadotropin-releasing hormone analog treatment, the predicted adult height using the Bayley-Pinneau method with the average bone age tables was the closest to the achieved adult height. Using the formulae, the predicted age at spontaneous menarche was 10.1 +/- 0.5 yr. The Gonadotropin-releasing hormone analog treatment significantly postponed this event until 11.9 +/- 0.7 yr in these ""idiopathic"" central precocious puberty girls, highlighting the beneficial effect of this treatment. CONCLUSION: Both initial adult height prediction methods are limited and must be used with caution. The prediction of the age at spontaneous menarche represents an innovative tool that can help in clinical decisions regarding pubertal suppression.
- FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies(2015) CORREA, Fernanda A.; TRARBACH, Ericka B.; TUSSET, Cintia; LATRONICO, Ana Claudia; MONTENEGRO, Luciana R.; CARVALHO, Luciani R.; FRANCA, Marcela M.; OTTO, Aline P.; COSTALONGA, Everlayny F.; BRITO, Vinicius N.; ABREU, Ana Paula; NISHI, Mirian Y.; JORGE, Alexander A. L.; ARNHOLD, Ivo J. P.; SIDIS, Yisrael; PITTELOUD, Nelly; MENDONCA, Berenice B.The genetic aetiology of congenital hypopituitarism (CH) is not entirely elucidated. FGFR1 and PROKR2 loss-of-function mutations are classically involved in hypogonadotrophic hypogonadism (HH), however, due to the clinical and genetic overlap of HH and CH; these genes may also be involved in the pathogenesis of CH. Using a candidate gene approach, we screened 156 Brazilian patients with combined pituitary hormone deficiencies (CPHD) for loss-of-function mutations in FGFR1 and PROKR2. We identified three FGFR1 variants (p.Arg448Trp, p.Ser107Leu and p.Pro772Ser) in four unrelated patients (two males) and two PROKR2 variants (p. Arg85Cys and p. Arg248Glu) in two unrelated female patients. Five of the six patients harbouring the variants had a first-degree relative that was an unaffected carrier of it. Results of functional studies indicated that the new FGFR1 variant p.Arg448Trp is a loss-of-function variant, while p.Ser107Leu and p.Pro772Ser present signalling activity similar to the wild-type form. Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca2+ pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity. The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype. The presence of the same variants in unaffected relatives implies that they cannot solely cause the phenotype. Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition.