MONICA MALHEIROS FRANCA
Projetos de Pesquisa
Unidades Organizacionais
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
3 resultados
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- 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
- Central Precocious Puberty Caused by a Heterozygous Deletion in the MKRN3 Promoter Region (vol 107, pg 127, 2018)(2018) MACEDO, D. B.; FRANCA, M. M.; MONTENEGRO, L. R.; CUNHA-SILVA, M.; BESSA, D. S.; ABREU, A. P.; KAISER, U. B.; MENDONCA, B. B.; JORGE, A. A. L.; BRITO, V. N.; LATRONICO, A. N.
- Central Precocious Puberty Caused by a Heterozygous Deletion in the MKRN3 Promoter Region(2018) MACEDO, Delanie B.; FRANCA, Monica M.; MONTENEGRO, Luciana R.; CUNHA-SILVA, Marina; BESSA, Danielle S.; ABREU, Ana Paula; KAISER, Ursula B.; MENDONCA, Berenice B.; JORGE, Alexander A. L.; BRITO, Vinicius N.; LATRONICO, Ana ClaudiaContext: Loss-of-function mutations in the coding region of MKRN3, a maternally imprinted gene at chromosome 15q11.2, are a common cause of familial central precocious puberty (CPP). Whether MKRN3 alterations in regulatory regions can cause CPP has not been explored to date. We aimed to investigate potential pathogenic variants in the promoter region of MKRN3 in patients with idiopathic CPP. Patients/Methods: A cohort of 110 patients with idiopathic CPP was studied. Family history of precocious sexual development was present in 25%. Mutations in the coding region of MKRN3 were excluded in all patients. Genomic DNA was extracted from peripheral blood leukocytes, and 1,100 nucleotides (nt) of the 5'-regulatory region of MKRN3 were amplified and sequenced. Luciferase assays were performed in GT1-7 cells transiently transfected with plasmids containing mutated and wild-type MKRN3 promoter. Results: We identified a rare heterozygous 4-nt deletion (c.-150_-147delTCAG; -38 to -41 nt upstream to the transcription start site) in the proximal promoter region of MKRN3 in a girl with CPP. In silico analysis predicted that this deletion would lead to the loss of a binding site for a downstream responsive element antagonist modulator (DREAM), a potential transcription factor for MKRN3 and GNRH1 expression. Luciferase assays demonstrated a significant reduction of MKRN3 promoter activity in transfected cells with a c.-150_-147delTCAG construct plasmid in both homozygous and heterozygous states when compared with cells transfected with the corresponding wild-type MKRN3 promoter region. Conclusion: A rare genetic alteration in the regulatory region of MKRN3 causes CPP. (c) 2018 S. Karger AG, Basel