LETICIA FERREIRA GONTIJO SILVEIRA
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LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
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article 8 Citação(ões) na Scopus Clinical and molecular aspects of congenital isolated hypogonadotropic hypogonadism(2011) TUSSET, Cintia; TRARBACH, Ericka B.; SILVEIRA, Leticia Ferreira Gontijo; BENEDUZZI, Daiane; MONTENEGRO, Luciana; LATRONICO, Ana ClaudiaCongenital isolated hypogonadotropic hypogonadism (IHH) is characterized by partial or complete lack of pubertal development due to defects in migration, synthesis, secretion or action of gonadotropin-releasing hormone (GnRH). Laboratory diagnosis is based on the presence of low levels of sex steroids, associated with low or inappropriately normal levels of pituitary gonadotropins (LH and FSH). Secretion of other pituitary hormones is normal, as well magnetic resonance imaging of the hypothalamohypophyseal tract, which shows absence of an anatomical defects. When IHH is associated with olfactory abnormalities (anosmia or hyposmia), it characterizes Kallmann syndrome. A growing list of genes is involved in the etiology of IHH, suggesting the heterogeneity and complexity of the genetic bases of this condition. Defects in olfactory and GnRH neuron migration are the etiopathogenic basis of Kallmann syndrome. Mutations in KAL1, FGFR1/FGF8, PROK2/PROKR2, NELF, CHD7, HS6ST1 and WDR11 are associated with defects in neuronal migration, leading to Kallmann syndrome. Notably, defects in FGFR1, FGF8, PROKR2, CHD7 and WDR11 are also associated with IHH, without olfactory abnormalities (normosmic IHH), although in a lower frequency. Mutations in KISS1R, TAC3/TACR3 and GNRH1/GNRHR are described exclusively in patients with normosmic IHH. In this paper, we reviewed the clinical, hormonal and genetic aspects of IHH. Arq Bras Endocrinol Metab. 2011;55(8):501-11- Molecular and Gene Network Analysis of Thyroid Transcription Factor 1 (TTF1) and Enhanced at Puberty (EAP1) Genes in Patients with GnRH-Dependent Pubertal Disorders(2013) CUKIER, Priscilla; WRIGHT, Hollis; RULFS, Tomke; SILVEIRA, Leticia Ferreira Gontijo; TELES, Milena Gurgel; MENDONCA, Berenice Bilharinho; ARNHOLD, Ivo J. P.; HEGER, Sabine; LATRONICO, Ana Claudia; OJEDA, Sergio R.; BRITO, Vinicius NahimeBackground/Aim: TTF1 and EAP1 are transcription factors that modulate gonadotropin-releasing hormone expression. We investigated the contribution of TTF1 and EAP1 genes to central pubertal disorders. Patients and Methods: 133 patients with central pubertal disorders were studied: 86 with central precocious puberty and 47 with normosmic isolated hypogonadotropic hypogonadism. The coding region of TTF1 and EAP1 were sequenced. Variations of polyglutamine and polyalanine repeats in EAP1 were analyzed by GeneScan software. Association of TTF1 and EAP1 to genes implicated in timing of puberty was investigated by meta-network framework GeneMANIA and Cytoscape software. Results: Direct sequencing of the TTF1 did not reveal any mutation or polymorphisms. Four EAP1 synonymous variants were identified with similar frequencies among groups. The most common EAP1 5'-distal polyalanine genotype was the homozygous 12/12, but the genotype 12/9 was identified in 2 central precocious puberty sisters without functional alteration in EAP1 transcriptional activity. TTF1 and EAP1 were connected, via genetic networks, to genes implicated in the control of menarche. Conclusion: No TTF1 or EAP1 germline mutations were associated with central pubertal disorders. TTF1 and EAP1 may affect puberty by changing expression in response to other members of puberty-associated gene networks, or by differentially affecting the expression of gene components of these networks. (C) 2013 S. Karger AG, Basel
- Approach to the Patient With Hypogonadotropic Hypogonadism(2013) SILVEIRA, Leticia Ferreira Gontijo; LATRONICO, Ana ClaudiaHypogonadotropic hypogonadism (HH) or secondary hypogonadism is defined as a clinical syndrome that results from gonadal failure due to abnormal pituitary gonadotropin levels. HH may result from either absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion. Several congenital and acquired causes, including functional and organic forms, have been associated with this condition. One important aspect of the HH diagnosis is that it may reflect the presence of a tumor of the hypothalamic pituitary region or even a systemic disease. On the other hand, functional forms of HH, characterized by a transient defect in GnRH secretion, are relatively common in women, in response to significant weight loss, exercise, or stress leading to hypothalamic amenorrhea. HH is typically characterized by low circulating sexual steroids associated with low or inappropriately normal gonadotropin levels. The precise and early diagnosis of HH can prevent negative physical and psychological sequelae, preserve normal peak bone mass, and restore the fertility in affected patients.
- New genetic factors implicated in human GnRH-dependent precocious puberty: The role of kisspeptin system(2011) TELES, Milena Gurgel; SILVEIRA, Leticia Ferreira Gontijo; TUSSET, Cintia; LATRONICO, Ana ClaudiaHuman puberty is triggered by the reemergence of GnRH pulsatile secretion with progressive activation of the gonadal function. A number of genes have been identified in the complex regulatory neuroendocrine network that controls puberty initiation. KISS1 and KISS1R genes, which encode kisspeptin and its cognate receptor, respectively, are considered crucial factors for acquisition of normal reproductive function. Recently, rare missense mutations and single nucleotide polymorphisms (SNPs) of the kisspeptin system were associated with puberty onset. Two gain-of-function mutations of the KISS1 and KISS1R genes were implicated in the pathogenesis of GnRH-dependent precocious puberty, previously considered idiopathic. These discoveries have yielded significant insights into the physiology and pathophysiology of this important life transition time. Here, we review the current molecular defects that are implicated in human GnRH-dependent precocious puberty.
- New genetic findings in a large cohort of congenital hypogonadotropic hypogonadism(2019) AMATO, Lorena Guimaraes Lima; MONTENEGRO, Luciana Ribeiro; LERARIO, Antonio Marcondes; JORGE, Alexander Augusto Lima; GUERRA JUNIOR, Gil; SCHNOLL, Caroline; RENCK, Alessandra Covallero; TRARBACH, Ericka Barbosa; COSTA, Elaine Maria Frade; MENDONCA, Berenice Bilharinho; LATRONICO, Ana Claudia; SILVEIRA, Leticia Ferreira GontijoContext: Congenital hypogonadotropic hypogonadism (CHH) is a rare condition caused by GnRH deficiency. Several genes have been associated with the pathogenesis of CHH, but most cases still remain without a molecular diagnosis. The advent of next-generation sequencing (NGS) has allowed the simultaneous genotyping of several regions, faster, making possible the extension of the genetic knowledge of CHH. Objective: Genetic characterization of a large cohort of Brazilian CHH patients. Design and patients: A cohort of 130 unrelated patients (91 males, 39 females) with CHH (75 normosmic CHH, 55 Kallmann syndrome) was studied using a panel containing 36 CHH-associated genes. Results: Potential pathogenic or probably pathogenic variants were identified in 43 (33%) CHH patients. The genes ANOS1, FGFR1 and GNRHR were the most frequently affected. A novel homozygous splice site mutation was identified in the GNRH1 gene and a deletion of the entire coding sequence was identified in SOX10. Deleterious variants in the IGSF10 gene were identified in two patients with reversible normosmic CHH. Notably, 6.9% of the patients had rare variants in more than one gene. Rare variants were also identified in SPRY4, IL17RD, FGF17, IGSF1 and FLRT3 genes. Conclusions: This is a large study of the molecular genetics of CHH providing new genetic findings for this complex and heterogeneous genetic condition. NGS has been shown to be a fast, reliable and effective tool in the molecular diagnosis of congenital CHH and being able to targeting clinical genetic testing in the future.
- Clinical and Genetic Characterization of a Constitutional Delay of Growth and Puberty Cohort(2020) BARROSO, Priscila Sales; JORGE, Alexander Augusto Lima; LERARIO, Antonio Marcondes; MONTENEGRO, Luciana Ribeiro; VASQUES, Gabriela Andrade; AMATO, Lorena Guimaraes Lima; SILVEIRA, Leticia Ferreira Gontijo; MENDONCA, Berenice Bilharinho; LATRONICO, Ana ClaudiaIntroduction:Constitutional delay of growth and puberty (CDGP) is the most prevalent cause of delayed puberty in both sexes. Family history of delayed puberty (2 or more affected members in a family) has been evidenced in 50-75% of patients with CDGP and the inheritance is often consistent with autosomal dominant pattern, with or without complete penetrance. However, the molecular basis of CDGP is not completely understood.Objective:To characterize the clinical and genetic features of a CDGP cohort.Methods:Fifty-nine patients with CDGP (48 boys and 11 girls) underwent careful and long-term clinical evaluation. Genetic analysis was performed using a custom DNA target enrichment panel designed to capture 36 known and candidate genes implicated with pubertal development.Results:All patients had spontaneous or induced pubertal development (transient hormonal therapy) prior to 18 years of age. The mean clinical follow-up time was 46 +/- 28 months. Male predominance (81%), short stature (91%), and family history of delayed puberty (59%) were the main clinical features of this CDGP -cohort. Genetic analyses revealed 15 rare heterozygous missense variants in 15 patients with CDGP (25%) in seven different genes (IGSF10,GHSR,CHD7,SPRY4, WDR11, SEMA3A,andIL17RD).IGSF10andGHSRwere the most prevalent affected genes in this group.Conclusions:Several rare dominant variants in genes implicated with GnRH migration and metabolism were identified in a quarter of the patients with familial or sporadic CDGP, suggesting genetic heterogeneity in this frequent pediatric condition.
- SIN3A defects associated with syndromic congenital hypogonadotropic hypogonadism: an overlap with Witteveen-Kolk syndrome(2023) SCHNOLL, Caroline; KREPISCHI, Ana Cristina Victorino; RENCK, Alessandra Covallero; AMATO, Lorena Guimaraes Lima; KULIKOWSKI, Leslie Domenici; DANTAS, Naiara Castelo Branco; COSTA, Elaine Maria Frade; MENDONCA, Berenice Bilharinho; LATRONICO, Ana Claudia; JORGE, Alexander Augusto de Lima; SILVEIRA, Leticia Ferreira GontijoIntroduction: Congenital hypogonadotropic hypogonadism (CHH) is a rare condition caused by GnRH deficiency. More than 40 genes have been associated with the pathogenesis of CHH, but most cases still remain without a molecular diagnosis. Mutations involving the same gene (e.g. FGFR1, PROK2/PROKR2, CHD7) were found to cause normosmic CHH and Kallmann syndrome, with and without associated phenotypes, illustrating the coexistence of CHH with signs of other complex syndromes. The Witteveen-Kolk syndrome (WITKOS), caused by defects of the SIN3A gene, is a heterogeneous disorder characterized by distinctive facial features, microcephaly, short stature, delayed cognitive and motor development. Although micropenis and cryptorchidism have been reported in this syndrome, WITKOS has not been formally associated with CHH so far. Patients and Methods: A man with Kallmann syndrome (KS) associated with mild syndromic features (S1) and a boy with global developmental delay, syndromic short stature, micropenis and cryptorchidism (S2), in whom common genetic defects associated with CHH and short stature had been previously excluded, were studied by either chromosomal microarray analysis (CMA) or whole exome sequencing (WES). Results: Rare SIN3A pathogenic variants were identified in these two unrelated patients with CHH phenotypic features. A 550 kb deletion at 15q24.1, including the whole SIN3A gene, was identified in S1, and a SIN3A nonsense rare variant (p.Arg471*) was detected in S2. Conclusion: These findings lead us to propose a link between SIN3A defects and CHH, especially in syndromic cases, based on these two patients with overlapping phenotypes of WITKOS and CHH.
bookPart Hipogonadismo masculino(2017) SILVEIRA, Leticia Ferreira Gontijo; COSTA, Elaine Maria Frade; LATRONICO, Ana Claudia- Molecular and Genetic Aspects of Congenital Isolated Hypogonadotropic Hypogonadism(2017) AMATO, Lorena Guimaraes Lima; LATRONICO, Ana Claudia; SILVEIRA, Leticia Ferreira GontijoCongenital isolated hypogonadotropic hypogonadism (IHH) is a clinically and genetically heterogenous disorder characterized by abnormal synthesis, secretion, or action of gonadotropin-releasing hormone, a key hypothalamic decapeptide that orchestrates the reproductive axis. Several modes of inheritance have been identified. A growing list of causative genes has been implicated in the molecular pathogenesis of syndromic and nonsyndromic IHH, largely contributing for better understanding the complex neuroendocrine control of reproduction. This article summarizes the great advances of molecular genetics of IHH and pointed up the heterogeneity and complexity of the genetic basis of this condition.