LETICIA FERREIRA GONTIJO SILVEIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
7 resultados
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- 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.
- Association between KISS1 rs5780218 promoter polymorphism and onset of growth hormone secreting pituitary adenoma(2019) AMORIM, Paulo V. G. H.; GRANDE, Isabella P. P.; BATISTA, Rafael L.; SILVEIRA, Leticia F. G.; FREIRE, Ane Caroline T. B.; BRONSTEIN, Marcello D.; JALLAD, Raquel S.; TRARBACH, Ericka B.Objectives. - This study analyzed the KISS1 c.-145delA (rs5780218) promoter polymorphism in a cohort of patients with growth hormone secreting pituitary adenoma (somatotropinoma) and controls, to investigate its role in the incidence of acromegaly and to assess patient/tumor characteristics. Material and methods rs5780218 allelic and genotypic distributions were compared between 49 somatotropinoma patients and 167 healthy controls. rs5780218 was also assessed in relation to patient characteristics and tumor aggressiveness, as characterized by tumor invasion and resistance to conventional therapy. The relationship between KISS1 mRNA expression and the rs5780218 genotype was also assessed in available pituitary tumor samples. Results. - The homozygous -/- variant genotype was associated with high rates of somatotropinoma (P < 0.01), but not with tumor invasiveness, patient characteristics or hormonal remission. KISS1 mRNA expression was much lower in somatotropinomas carrying the deleted allele than in homozygous wild type AA. Conclusions. - In this pilot study, the rs5780218 promoter polymorphism was evaluated in pituitary adenoma, and showed a possible association with the incidence of somatotropinoma but not with tumor progression.
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):501-11article 0 Citação(ões) na Scopus Nonsense Mutations in FGF8 Gene Causing Different Degrees of Human Gonadotropin-Releasing Deficiency (vol 95, pg 3491, 2010)(2011) TRARBACH, Ericka B.; ABREU, Ana Paula; FERREIRA, Leticia; SILVEIRA, Gontijo; GARMES, Heraldo Mendes; BAPTISTA, Maria TerezaM.; TELES, Milena Gurgel; COSTA, ElaineM. F.; MOHAMMADI, Moosa; PITTELOUD, Nelly; MENDONCA, Berenice B.; LATRONICO, Ana Claudia- Combined use of multiplex ligation-dependent probe amplification and automatic sequencing for identification of KAL1 defects in patients with Kallmann syndrome(2013) MONTENEGRO, Luciana Ribeiro; SILVEIRA, Leticia F. G.; TUSSET, Cintia; CASTRO, Margaret de; VERSIANI, Beatriz R.; LATRONICO, Ana Claudia; MENDONCA, Berenice Bilharinho; TRARBACH, Ericka B.Objective: To investigate the role of KAL1 abnormalities in Brazilian patients with Kallmann syndrome. Design: In vitro experiments. Setting: Academic medical center. Patient(s): One hundred fifteen Brazilian patients (98 men) with Kallmann syndrome. Intervention(s): Peripheral blood leukocytes were used to obtain DNA. Main Outcome Measure(s): Direct sequencing and multiplex ligation-dependent probe amplification were used to identify KAL1 abnormalities. Result(s): We identified four KAL1 mutations (p.Met1?, p.Ala33Glyfs, p.Arg257*, and p.Trp462*) and two multiple exon deletions (exons 1-2 and 3-14) in six new male patients. Overall, 17 KAL1 defects (14.8%) were identified in the entire cohort of patients with Kallmann syndrome, including previously studied cases. KAL1-mutated patients presented with a more severe reproductive and nonreproductive phenotype (synkinesia, renal malformations, cryptorchidism, and anatomic olfactory abnormalities) in comparison with patients without KAL1 mutations. Intragenic deletions were one of the most often encountered defects (29.4%). These deletions can be missed by polymerase chain reaction (PCR) due to Yq11.2 KAL1 pseudogene (KALP) spurious amplification. Conclusion(s): These results indicate that intragenic multiexon deletions are one of the most frequent KAL1 abnormalities, which can be more accurately detected by multiplex ligation-dependent probe amplification. In addition, KAL1 sequencing results should be interpreted with caution, and stringency conditions of the PCR reaction should be adjusted to avoid pseudogene amplification. (C) 2013 by American Society for Reproductive Medicine.
- Role of gonadotropin-releasing hormone receptor mutations in patients with a wide spectrum of pubertal delay(2014) BENEDUZZI, Daiane; TRARBACH, Ericka B.; MIN, Le; JORGE, Alexander A. L.; GARMES, Heraldo M.; RENK, Alessandra Covallero; FICHNA, Marta; FICHNA, Piotr; ARANTES, Karina A.; COSTA, Elaine M. F.; ZHANG, Anna; ADEOLA, Oluwaseun; WEN, Junping; CARROLL, Rona S.; MENDONCA, Berenice B.; KAISER, Ursula B.; LATRONICO, Ana Claudia; SILVEIRA, Leticia F. G.Objective: To analyze the GNRHR in patients with normosmic isolated hypogonadotropic hypogonadism (IHH) and constitutional delay of growth and puberty (CDGP). Design: Molecular analysis and in vitro experiments correlated with phenotype. Setting: Academic medical center. Patient(s): A total of 110 individuals with normosmic IHH (74 male patients) and 50 with CDGP. Intervention(s): GNRHR coding region was amplified and sequenced. Main Outcome Measure(s): Novel variants were submitted to in vitro analysis. Frequency of mutations and genotype-phenotype correlation were analyzed. Microsatellite markers flanking GNRHR were examined in patients carrying the same mutation to investigate a possible founder effect. Result(s): Eleven IHH patients (10%) carried biallelic GNRHR mutations. In vitro analysis of novel variants (p.Y283H and p.V134G) demonstrated complete inactivation. The founder effect study revealed that Brazilian patients carrying the p.R139H mutation shared the same haplotype. Phenotypic spectrum in patients with GNRHR mutations varied from complete GnRH deficiency to partial and reversible IHH, with a relatively good genotype-phenotype correlation. One boy with CDGP was heterozygous for the p.Q106R variant, which was not considered to be pathogenic. Conclusion(s): GNRHR mutations are a frequent cause of congenital normosmic IHH and should be the first candidate gene for genetic screening in this condition, especially in autosomal recessive familial cases. The founder effect study suggested that the p.R139H mutation arises from a common ancestor in the Brazilian population. Finally, mutations in GNRHR do not appear to be involved in the pathogenesis of CDGP. (C) 2014 by American Society for Reproductive Medicine.
- Novel mutation in the gonadotropin-releasing hormone receptor (GNRHR) gene in a patient with normosmic isolated hypogonadotropic hypogonadism(2012) BENEDUZZI, Daiane; TRARBACH, Ericka B.; LATRONICO, Ana Claudia; MENDONCA, Berenice Bilharinho de; SILVEIRA, Leticia F. G.We report a novel GNRHR mutation in a male with normosmic isolated hypogonadotropic hypogonadism (nIHH). The coding region of the GNRHR gene was amplified and sequenced. Three variants p.[Asn10Lys; Gln11Lys]; [Tyr283His] were identified in the GNRHR coding region in a male with sporadic complete nIHH. The three variants were absent in the controls (130 normal adults). Familial segregation showed that the previously described p. Asn10Lys and p. Gln11Lys are in the same allele, in compound heterozygozity with the novel variant p. Tyr283His. The p.[Asn10Lys; Gln11Lys] are known inactivating mutations. The p. Tyr283His affects a well-conserved residue, and in silico analysis suggested it is a deleterious variant. We describe a novel GNRHR mutation in a male with nIHH. Absence of the mutation in the control group, conservation among species, in silico analysis, and familial segregation suggest that p. Tyr283His, which was identified in compound heterozygozity with the p.[Asn10Lys; Gln11Lys] variants, is an inactivating mutation.