19 research outputs found

    Homozygous Inactivating Mutation In Nanos3 In Two Sisters With Primary Ovarian Insufficiency.

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    Despite the increasing understanding of female reproduction, the molecular diagnosis of primary ovarian insufficiency (POI) is seldom obtained. The RNA-binding protein NANOS3 poses as an interesting candidate gene for POI since members of the Nanos family have an evolutionarily conserved function in germ cell development and maintenance by repressing apoptosis. We performed mutational analysis of NANOS3 in a cohort of 85 Brazilian women with familial or isolated POI, presenting with primary or secondary amenorrhea, and in ethnically-matched control women. A homozygous p.Glu120Lys mutation in NANOS3 was identified in two sisters with primary amenorrhea. The substituted amino acid is located within the second C2HC motif in the conserved zinc finger domain of NANOS3 and in silico molecular modelling suggests destabilization of protein-RNA interaction. In vitro analyses of apoptosis through flow cytometry and confocal microscopy show that NANOS3 capacity to prevent apoptosis was impaired by this mutation. The identification of an inactivating missense mutation in NANOS3 suggests a mechanism for POI involving increased primordial germ cells (PGCs) apoptosis during embryonic cell migration and highlights the importance of NANOS proteins in human ovarian biology.201478746

    Nr5a1 Loss-of-function mutations lead to 46,xy partial gonadal dysgenesis phenotype: report of three novel mutations

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    Mutations in the NR5A1 gene, which encodes the steroidogenic factor 1 (SF1), are responsible for different phenotypes of disorders of sex development (DSD), such as bilateral anorchia and hypospadias. Furthermore, they can be associated with primary amenorrhea, premature ovarian failure, male infertility, adrenal tumors, and endometriosis. Direct sequencing of the 7 NR5A1 exons including similar to 1,000 bp of the 5'-upstream and 3'-downstream regions and all intron-exon boundaries was performed in patients with DSD. Three different in silico tools were used to assess the consequences of a splice site mutation. As a result, 3 novel NR5A1 mutations were identified in 3 patients with 46,XY partial gonadal dysgenesis: p.Lys38* and p.Leu80Trpfs*8 lead to premature translation termination codons within the SF1 DNA-binding domain, and the intronic nucleotide substitution c.1138+1G>T at the intron 6 donor splice site is considered to modify correct splicing. We assume that the anomalous mRNA produced as a result of plys38* and p.Leu80Trpfs*8 will be degraded by nonsense-mediated mRNA decay even before translation, leading to SF1 haploinsufficiency. The c.1138+1G>T mutation is expected to produce a truncated protein. Heterozygous SF1 loss-of-function mutations in these cases resulted in mild DSD manifestations, such as dysgenetic testes, spontaneous puberty, and preserved adrenal function. (C) 2016 S. Karger AG, Basel.104191199CNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informação2013/05603-

    Phenotype-genotype correlation in nr5a1 gene remains elusive: heterozygosis for p.d293n mutation also leads dsd phenotype

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    We report on a patient with XY partial gonadal dysgenesis (PGD) with a heterozygous mutation that had already been described in homozygous patients from a family with different phenotypes. Methods: Our patient was referred with 14 days of age due to sex ambiguity. He had a 1.5-cm phallus, penoscrotal hypospadias, and both gonads were in the labioscrotal folds. Horm Res Paediatr 2017;88(suppl 1):1–628 Karyotype was 46,XY. At 6 weeks of age he had normal FSH, DHEA and androstenedione, whereas LH, 17-OHprogesterone and testosterone were elevated, slightly elevated and low, respectively. ACTH test resulted normal but there was no response to hCH test performed at 7 months. Antimullerian hormone was also low. He received a male sex assignment and underwent hypospadias repair. He had a right streak gonad and a left dysgenetic testis, leading to the diagnosis of XY PGD. Spontaneous puberty started at 12 years and progressed normally. At 16 years he had high FSH and LH but normal testosterone. Whole exome sequencing was performed to search for patogenic mutations in genes involved in testis differentiation. Results: Whole exome sequencing revealed heterozygosis of the c.877Ggt;A transition within exon 5 of NR5A1. This change leads to p.D293N mutation that had already been described in four homozygous members of a family: one with XY PGD, one with XX complete gonadal dysgenesis (CGD) and two with XY CGD. Heterozygous members of the family were phenotypically normal. The mother of the present patient was born in the same little town where that family originated. Conclusions: To our knowledge, this is the first p.D293N heterozygous individual to present DSD. The recessive inheritance for this mutation concluded on basis of that family pattern and on the relatively high level of residual activity of the mutated SF-1 is no longer appropriated. SF-1 acts in a dose-dependent manner and regulates many other genes involved in sex differentiation process, which could explain the broad spectrum of phenotypes caused by the same mutation. The present case illustrates the difficulty in establishing an appropriate phenotype-genotype correlation and highlights the importance of genetic knowledge for the correlation of NR5A1 mutations with clinical phenotypes881P1 - 151620220

    Wt1 haploinsufficiency supports milder renal manifestation in two patients with denys-drash syndrome

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    Denys-Drash syndrome (DDS) is characterized by nephropathy, genital abnormalities, and predisposition to Wilms' tumor. DDS patients usually present heterozygous de novo germline WT1 mutations. The WT1 gene comprises 10 exons encoding the N-terminal transactivation and the C-terminal DNA-binding regions. Two unrelated patients with genital ambiguity and Wilms' tumor were analyzed by sequencing of the WT1 gene, and 3 mutations in exon 1 were identified of which 2 are novel. Patient 1 carried a c.555delC mutation that causes a frameshift and a premature stop codon. Patient 2 carried both c.421A>C and c. 424C>T aberrations that lead to the missense p.Lys141Gln and the nonsense p. Lys142 * mutation, respectively. As both patients were heterozygous for the mutations, we tested their parents who did not carry any mutation. Therefore, the 3 WT1 mutations occurred de novo in both patients. Heterozygous mutations result in WT1 haploinsufficiency as they impair protein production. They are associated with a milder DDS phenotype as observed in the patients studied here.1113439FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2012/51109-0478444/08-7; 141072/201

    Screening of targeted panel genes in Brazilian patients with primary ovarian insufficiency.

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    Primary ovarian insufficiency (POI) is a heterogeneous disorder associated with several genes. The majority of cases are still unsolved. Our aim was to identify the molecular diagnosis of a Brazilian cohort with POI. Genetic analysis was performed using a customized panel of targeted massively parallel sequencing (TMPS) and the candidate variants were confirmed by Sanger sequencing. Additional copy number variation (CNV) analysis of TMPS samples was performed by CONTRA. Fifty women with POI (29 primary amenorrhea and 21 secondary amenorrhea) of unknown molecular diagnosis were included in this study, which was conducted in a tertiary referral center of clinical endocrinology. A genetic defect was obtained in 70% women with POI using the customized TMPS panel. Twenty-four pathogenic variants and two CNVs were found in 48% of POI women. Of these variants, 16 genes were identified as BMP8B, CPEB1, INSL3, MCM9, GDF9, UBR2, ATM, STAG3, BMP15, BMPR2, DAZL, PRDM1, FSHR, EIF4ENIF1, NOBOX, and GATA4. Moreover, a microdeletion and microduplication in the CPEB1 and SYCE1 genes, respectively, were also identified in two distinct patients. The genetic analysis of eleven patients was classified as variants of uncertain clinical significance whereas this group of patients harbored at least two variants in different genes. Thirteen patients had benign or no rare variants, and therefore the genetic etiology remained unclear. In conclusion, next-generation sequencing (NGS) is a highly effective approach to identify the genetic diagnoses of heterogenous disorders, such as POI. A molecular etiology allowed us to improve the disease knowledge, guide decisions about prevention or treatment, and allow familial counseling avoiding future comorbidities

    Functional impact of novel androgen receptor mutations on the clinical manifestation of androgen insensitivity syndrome

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOAndrogens are responsible for the development and maintenance of male sex characteristics. Dysfunctions in androgen action due to mutations in the androgen receptor gene (AR) can lead to androgen insensitivity syndrome (AIS) that can be classified as mild115-6238247FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2009/08320-92008/01964-5sem informaçã

    Diagnosis of 5α-reductase type 2 deficiency: Contribution of anti-Müllerian hormone evaluation

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    Aim: To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5α-reductase 2 deficiency. Patients and methods: Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. Results: Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. Conclusions: Prepubertal patients with 5α-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells. © Freund Publishing House Ltd., London

    Diagnosis Of 5alpha-reductase Type 2 Deficiency: Contribution Of Anti-müllerian Hormone Evaluation.

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    To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5alpha-reductase 2 deficiency. Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. Prepubertal patients with 5alpha-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells.181383-
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