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1.
Genet Med ; 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568805

RESUMO

PURPOSE: Recent studies have identified suggestive prenatal features of RASopathies (e.g., increased nuchal translucency [NT], cystic hygroma [CH], hydrops, effusions, congenital heart diseases [CHD], polyhydramnios, renal anomalies). Our objective is to clarify indications for RASopathy prenatal testing. We compare genotype distributions between pre- and postnatal populations and propose genotype-phenotype correlations. METHODS: Three hundred fifty-two chromosomal microarray-negative cases sent for prenatal RASopathy testing between 2012 and 2019 were collected. For most, 11 RASopathy genes were tested. Postnatal cohorts (25 patients with available prenatal information and 108 institutional database genotypes) and the NSeuroNet database were used for genotypic comparisons. RESULTS: The overall diagnostic yield was 14% (50/352), with rates >20% for effusions, hydrops, and CHD. Diagnostic yield was significantly improved in presence of hypertrophic cardiomyopathy (HCM), persistent or associated CH, any suggestive finding combined with renal anomaly or polyhydramnios, or ≥2 ultrasound findings. Largest prenatal contributors of pathogenic variants were PTPN11 (30%), RIT1 (16%), RAF1 (14%), and HRAS (12%), which considerably differ from their prevalence in postnatal populations. HRAS, LZTR1, and RAF1 variants correlated with hydrops/effusions, and RIT1 with prenatal onset HCM. CONCLUSION: After normal chromosomal microarray, RASopathies should be considered when any ultrasound finding of lymphatic dysplasia or suggestive CHD is found alone or in association.

2.
Fam Cancer ; 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33210232

RESUMO

We present a 24-year-old female patient affected by neurofibromatosis type 1 (NF1) who developed a malignant phyllodes tumor of the breast. The molecular studies showed that the patient carried a heterozygous inactivating deleterious variant in BRCA1 inherited from the father associated with a germline de novo pathogenic alteration in NF1; the tumor presented a biallelic inactivation of both genes. Therefore, tumor analyses helped to establish that the germline NF1 and BRCA1 variants were in cis on the paternal chromosome. This last information is important to provide adequate genetic counselling regarding the risk of recurrence in the offspring, as well as opportunity for early intervention. In conclusion, we present the first case of a malignant phyllodes tumor of the breast in patient carrying pathogenic variants in NF1 and BRCA1. Further studies will be necessary to understand if the phyllodes histotype represents a very rare component of NF1-associated breast cancer.

3.
Acta Neuropathol ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025139

RESUMO

Schwannomatosis (SWNTS) is a genetic cancer predisposition syndrome that manifests as multiple and often painful neuronal tumors called schwannomas (SWNs). While germline mutations in SMARCB1 or LZTR1, plus somatic mutations in NF2 and loss of heterozygosity in chromosome 22q have been identified in a subset of patients, little is known about the epigenomic and genomic alterations that drive SWNTS-related SWNs (SWNTS-SWNs) in a majority of the cases. We performed multiplatform genomic analysis and established the molecular signature of SWNTS-SWNs. We show that SWNTS-SWNs harbor distinct genomic features relative to the histologically identical non-syndromic sporadic SWNs (NS-SWNS). We demonstrate the existence of four distinct DNA methylation subgroups of SWNTS-SWNs that are associated with specific transcriptional programs and tumor location. We show several novel recurrent non-22q deletions and structural rearrangements. We detected the SH3PXD2A-HTRA1 gene fusion in SWNTS-SWNs, with predominance in LZTR1-mutant tumors. In addition, we identified specific genetic, epigenetic, and actionable transcriptional programs associated with painful SWNTS-SWNs including PIGF, VEGF, MEK, and MTOR pathways, which may be harnessed for management of this syndrome.

5.
Dermatol Online J ; 26(8)2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32941720

RESUMO

Pancreatic cancer-melanoma syndrome (PCMS) is an inherited condition in which mutation carriers have an increased risk of malignant melanoma and/or pancreatic cancer. About 30% of PCMS cases carry mutations in CDKN2A. This gene encodes several protein isoforms, one of which, known as p16, regulates the cell-cycle by interacting with CDK4/CDK6 kinases and with several non-CDK proteins. Herein, we report on a novel CDKN2A germline in-frame deletion (c.52_57delACGGCC) found in an Italian family with PCMS. By segregation analysis, the c.52_57delACGGCC was proven to segregate in kindred with cutaneous melanoma (CM), in kindred with CM and pancreatic cancer, and in a single case presenting only with pancreatic cancer. In the literature, duplication mapping in the same genic region has been already reported at the germline level in several unrelated CM cases as a variant of unknown clinical significance. A computational approach for studying the effect of mutational changes over p16 protein structure showed that both the deletion and the duplication of the c.52_57 nucleotides result in protein misfolding and loss of interactors' binding. In conclusion, the present results argue that the quantitative alteration of nucleotides c.52_57 has a pathogenic role in p16 function and that the c.52_57delACGGCC is associated with PCMS.

6.
Cancers (Basel) ; 12(2)2020 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-31991861

RESUMO

Germline protein truncating variants (PTVs) in the FANCM gene have been associated with a 2-4-fold increased breast cancer risk in case-control studies conducted in different European populations. However, the distribution and the frequency of FANCM PTVs in Europe have never been investigated. In the present study, we collected the data of 114 European female breast cancer cases with FANCM PTVs ascertained in 20 centers from 13 European countries. We identified 27 different FANCM PTVs. The p.Gln1701* PTV is the most common PTV in Northern Europe with a maximum frequency in Finland and a lower relative frequency in Southern Europe. On the contrary, p.Arg1931* seems to be the most common PTV in Southern Europe. We also showed that p.Arg658*, the third most common PTV, is more frequent in Central Europe, and p.Gln498Thrfs*7 is probably a founder variant from Lithuania. Of the 23 rare or unique FANCM PTVs, 15 have not been previously reported. We provide here the initial spectrum of FANCM PTVs in European breast cancer cases.

7.
Respiration ; 98(2): 125-132, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31266032

RESUMO

BACKGROUND: Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal-dominant inherited disorder characterized by inactivation of the gene Folliculin (FLCN), pulmonary cysts with recurrent spontaneous pneumothorax, dermatological lesions, and an increased risk of developing renal malignancies. OBJECTIVES: We aimed to investigate the real prevalence of BHDS and its prevalence among patients with a familial history of pneumothorax. METHODS: From July 2014 to December 2016, we consecutively studied all patients with spontaneous pneumothorax and a positive family history for the same condition referring to our Institution. The suspicious cases underwent genetic analysis of the BHDS-causative gene FLCN. FLCN-positive cases were further evaluated with routine blood tests, chest radiography, chest CT, abdominal MRI, and dermatological evaluation. RESULTS: Among 114 patients admitted with spontaneous pneumothorax, 7 patients had a family history of pneumothorax, and 6/7 (85.7%) patients had positive genetic test for FLCN as well as 7/13 family members. Pulmonary cysts were found in all patients with a FLCN-positive genetic test. Most patients (10/13, 76.9%) had tiny pulmonary cysts less than 1 cm in diameter. The vast majority of cysts were intraparenchymal (12/13, 92.3%) and located in lower lobes. Dermatological lesions were found in 7/13 (54%) patients, renal cysts in 4/13 (31%) patients, and renal cancer in 1 (1/13, 7.7%) patient. CONCLUSIONS: Although BHDS is considered a rare disease, BHDS underlies spontaneous pneumothorax more often than usually believed, especially whenever a family history of pneumothorax is present. Diagnosis of BHDS is essential to start monitoring patients for the risk of developing renal malignancies.


Assuntos
Síndrome de Birt-Hogg-Dubé/diagnóstico , Anamnese , Pneumotórax/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Síndrome de Birt-Hogg-Dubé/epidemiologia , Síndrome de Birt-Hogg-Dubé/genética , Cistos/diagnóstico por imagem , Feminino , Testes Genéticos , Humanos , Doenças Renais Císticas/diagnóstico por imagem , Pneumopatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Prevalência
8.
J Mol Diagn ; 20(1): 87-94, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29061375

RESUMO

The efficiency of a novel targeted next-generation sequencing (NGS) test, the Devyser BRCA kit, for a comprehensive analysis of all 48 coding exons of the high-risk breast/ovarian cancer susceptibility genes BRCA1 and BRCA2 has been assessed. The new assay intended to detect nucleotide substitutions, small deletions/insertions, and large deletions/duplications. To document the false-negative and false-positive rates of the NGS assay in the hands of end users, 48 samples with previously identified 444 small variants and seven gross rearrangements were analyzed, showing 100% concordance with gold standards. Furthermore, all other 43 variants (42 single-nucleotide variation or insertion/deletion variation and one copy number variation, whose significance is or may be of clinical value), which were called by the NGS assay in a prospectively analyzed 179-sample set, were confirmed by Sanger sequencing or multiplex ligation probe amplification, according to their nature. We conclude that the Devyser BRCA kit performed satisfactorily for use in a clinical laboratory.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação/genética , Variações do Número de Cópias de DNA/genética , Éxons/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética , Reprodutibilidade dos Testes
9.
J Neurooncol ; 137(1): 33-38, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29230670

RESUMO

In sporadic schwannomas, inactivation of both copies of the NF2 tumor suppressor gene on 22q is common. Constitutional mutations of SMARCB1 are responsible of schwannomatosis, an inherited tumor predisposition syndrome, characterized by the development of multiple schwannomas. We analysed the frequency of copy number changes on chromosome 22 and the mutation of NF2 and SMARCB1 in 26 sporadic schwannomas. We found two spinal schwannomas with an identical somatic missense mutation in SMARCB1 exon 9: p.(Arg377His). Both SMARCB1 mutated schwannomas had LOH of 22q and one of them harbored an inactivating mutation of NF2. The p.(Arg377His) change was not found in a series of 28 vestibular schwannomas. Our data indicate that mutations affecting SMARCB1 play a role in the development or progression of a small subset of spinal schwannomas and that biallelic inactivation of SMARCB1 may cooperate with deficiency of NF2 function in schwannoma tumorigenesis according to the "four-hit/three events" mechanism of tumorigenesis that we demonstrated in schwannomatosis-associated schwannomas.


Assuntos
Neurilemoma/genética , Neurofibromina 2/genética , Proteína SMARCB1/genética , Neoplasias da Coluna Vertebral/genética , Adulto , Idoso , Criança , Cromossomos Humanos Par 22/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neuroma Acústico/genética , Adulto Jovem
10.
Childs Nerv Syst ; 33(6): 933-940, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28365909

RESUMO

BACKGROUND: The INI1/SMARCB1 gene protein product has been implicated in the direct pathogenesis of schwannomas from patients with one form of schwannomatosis [SWNTS1; MIM # 162091] showing a mosaic pattern of loss of protein expression by immunohistochemistry [93% in familial vs. 55% in sporadic cases]. AIM OF STUDY: To verify whether such INI1/SMARCB1 mosaic pattern could be extended to all schwannomas arising in the sporadic and familial schwannomatoses [i.e. to SMARCB1-related (SWNTS1) or LZTR1-related (SWNTS2) schwannomatosis or to SMARCB1/LZTR1-negative schwannomatosis] and whether it could be involved in classical NF2 or solitary peripheral schwannomas METHODS: We blindly analysed schwannoma samples obtained from a total of 22 patients including (a) 2 patients (2 males; aged 38 and 55 years) affected by non-familial SMARCB1-associated schwannomatosis (SWTNS1); (b) 1 patient (1 female; aged 33 years) affected by familial schwannomatosis (SWTNS1/ SMARCB1 germ line mutations); (c) 5 patients (3 males, 2 females; aged 33 to 35 years) affected by non-familial (sporadic) LZTR1-associated schwannomatosis (SWNTS2); (d) 3 patients (3 males; aged 35 to 47 years) affected by familial schwannomatosis (SWTNS2/ LZTR1 germ line mutations); (e) 2 patients (1 male, 1 female; aged 63 and 49 years, respectively) affected by non-familial schwannomatosis (SWTNS, negative for SMARCB1, LZTR1 and NF2 gene mutations); (f) 4 patients (3 males, 1 females; aged 15 to 24 years) affected by classical NF2 (NF2: harbouring NF2 germ line mutations; and (g) 5 patients (3 males, 2 females; aged 33 to 68 years) who had solitary schwannomas. [follow-up = 15-30 years; negative for constitutional/somatic mutation analysis for the SMARCB1, LZTR1 and NF2 genes] were (blindly) analyzed. The INI1/SMARCB1 immunostaining pattern was regarded as (1) diffuse positive nuclear staining [= retained expression] or (2) mosaic pattern [mixed positive/negative nuclei = loss of expression in a subset of tumour cells]. RESULTS: All solitary peripheral schwannomas and NF2-associated vestibular schwannomas showed diffuse nuclear INI1/SMARCB1 staining in 97-100% of neoplastic cells; schwannomas obtained from all cases of non-familial and familial schwannomatosis and NF2-associated non-vestibular schwannomas showed a mosaic pattern ranging from 10 to 70% of INI1/SMARCB1-positive expression. We did not record a complete lack of nuclear staining. CONCLUSIONS: The present data suggests that (a) mosaic loss of immunohistochemical INI1/SMARCB1 expression, despite the interlesional variability, is a reliable marker of schwannomatosis regardless of the involved gene and it might help in the differential diagnosis of schwannomatosis vs. solitary schwannomas and (b) INI1/SMARCB1 expression is not useful in the differential with mosaic NF2, since NF2-associated peripheral schwannomas show the same immunohistochemical pattern.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes da Neurofibromatose 2/fisiologia , Neuroma Acústico/genética , Neuroma Acústico/patologia , Proteína SMARCB1/biossíntese , Proteína SMARCB1/genética , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurilemoma/genética , Neurilemoma/metabolismo , Neurilemoma/patologia , Neuroma Acústico/metabolismo , Adulto Jovem
11.
Hum Mutat ; 38(1): 64-77, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27629256

RESUMO

Pathogenicity assessment of DNA variants in disease genes to explain their clinical consequences is an integral component of diagnostic molecular testing. The International Society for Gastrointestinal Hereditary Tumors (InSiGHT) has developed specific criteria for the interpretation of mismatch repair (MMR) gene variants. Here, we performed a systematic investigation of 24 MLH1 and MSH2 variants. The assessments were done by analyzing population frequency, segregation, tumor molecular characteristics, RNA effects, protein expression levels, and in vitro MMR activity. Classifications were confirmed for 15 variants and changed for three, and for the first time determined for six novel variants. Overall, based on our results, we propose the introduction of some refinements to the InSiGHT classification rules. The proposed changes have the advantage of homogenizing the InSIGHT interpretation criteria with those set out by the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium for the BRCA1/BRCA2 genes. We also observed that the addition of only few clinical data was sufficient to obtain a more stable classification for variants considered as "likely pathogenic" or "likely nonpathogenic." This shows the importance of obtaining as many as possible points of evidence for variant interpretation, especially from the clinical setting.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Alelos , Processamento Alternativo , Biomarcadores Tumorais , Mapeamento Cromossômico , Bases de Dados Genéticas , Frequência do Gene , Ligação Genética , Genótipo , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Repetições de Microssatélites , Proteína 1 Homóloga a MutL/metabolismo , Proteína 2 Homóloga a MutS/metabolismo , Mutação , Fenótipo , Regiões Promotoras Genéticas
12.
Fam Cancer ; 15(1): 123-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26342593

RESUMO

Rhabdoid tumors are aggressive malignancies that show loss-of-function mutations of SMARCB1 gene, a member of the SWI/SNF chromatin-remodeling complex controlling gene transcription. One-third of patients affected by rhabdoid tumor harbor a germ-line mutation of SMARCB1 defining a rhabdoid tumor predisposition syndrome. The occurrence of a second somatic mutation determines the development of neoplasia in a two-hit model. Most germ-line mutations occur de novo, and few cases of recurrence in a sibship have been described. Here we report on a new Italian family with recurrence of SMARCB1 germ-line deletion in two siblings due to gonadal mosaicism. The deletion was identified in the 9-month-old proband with malignant rhabdoid tumor of the right kidney and disseminated metastases. Testing of both parents confirmed the de novo origin of the mutation, but recurrence was then detected prenatally in a new pregnancy. This is the sixth family with malignant rhabdoid tumor predisposition syndrome with the recurrence of the same germ-line SMARCB1 mutation in the sibship but not in healthy parents, suggesting that gonadal mosaicism is a less rare event than supposed. The clinical outcome in our patient confirms previous data of poorer outcome in patients with rhabdoid tumor predisposition syndrome.


Assuntos
Neoplasias Encefálicas/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença/genética , Neoplasias Renais/genética , Tumor Rabdoide/genética , Fatores de Transcrição/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Lactente , Perda de Heterozigosidade , Masculino , Mosaicismo , Reação em Cadeia da Polimerase Multiplex , Linhagem , Gravidez , Diagnóstico Pré-Natal , Proteína SMARCB1 , Irmãos
13.
PLoS One ; 10(6): e0129099, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26066488

RESUMO

The accurate detection of low-allelic variants is still challenging, particularly for the identification of somatic mosaicism, where matched control sample is not available. High throughput sequencing, by the simultaneous and independent analysis of thousands of different DNA fragments, might overcome many of the limits of traditional methods, greatly increasing the sensitivity. However, it is necessary to take into account the high number of false positives that may arise due to the lack of matched control samples. Here, we applied deep amplicon sequencing to the analysis of samples with known genotype and variant allele fraction (VAF) followed by a tailored statistical analysis. This method allowed to define a minimum value of VAF for detecting mosaic variants with high accuracy. Then, we exploited the estimated VAF to select candidate alterations in NF2 gene in 34 samples with unknown genotype (30 blood and 4 tumor DNAs), demonstrating the suitability of our method. The strategy we propose optimizes the use of deep amplicon sequencing for the identification of low abundance variants. Moreover, our method can be applied to different high throughput sequencing approaches to estimate the background noise and define the accuracy of the experimental design.


Assuntos
Genes da Neurofibromatose 2 , Mosaicismo , Reação em Cadeia da Polimerase Multiplex/métodos , Neurofibromatose 2/genética , Polimorfismo de Nucleotídeo Único , Frequência do Gene , Humanos , Reação em Cadeia da Polimerase Multiplex/normas , Mutação , Sensibilidade e Especificidade
14.
Hum Pathol ; 46(8): 1226-31, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26001331

RESUMO

Schwannomatosis is a tumor predisposition syndrome characterized by development of multiple intracranial, spinal, and peripheral schwannomas. Constitutional alterations in either SMARCB1 or LZTR1 on 22q are responsible of the phenotype. We describe a 34-year-old woman who developed multiple benign peripheral sheath tumors and a uterine leiomyosarcoma. The patient carried a de novo constitutional alteration in exon 8 of SMARCB1, c.1118G > A, which destroyed the splice donor site of intron 8. Two schwannomas and the leiomyosarcoma of the patient retained the SMARCB1 mutation; in addition, the tumors showed loss of the normal chromosome 22. In conclusion, our findings enlarged the spectrum of SMARCB1-predisposing tumors and demonstrated, for the first time, the association of a malignant smooth muscle tumor to schwannomatosis. Therefore, clinicians should definitely be aware that a constitutional SMARCB1 mutation, which mainly predisposes to benign nerve sheath tumors, may also predispose to aggressive neoplasms throughout life, within an unexpected spectrum.


Assuntos
Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Leiomiossarcoma/genética , Neoplasias Primárias Múltiplas/genética , Neurilemoma/genética , Neurofibromatoses/genética , Neoplasias Cutâneas/genética , Fatores de Transcrição/genética , Neoplasias Uterinas/genética , Adolescente , Adulto , Idade de Início , Feminino , Predisposição Genética para Doença/genética , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase , Proteína SMARCB1 , Adulto Jovem
15.
Breast Cancer Res ; 17: 61, 2015 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-25925750

RESUMO

INTRODUCTION: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. METHODS: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. RESULTS: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. CONCLUSIONS: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.


Assuntos
Neoplasias da Mama/genética , Genes BRCA2 , Genes Mitocondriais , Heterozigoto , Mutação , Proteína BRCA1/genética , Feminino , Predisposição Genética para Doença , Haplótipos , Humanos , Filogenia , Risco
16.
Nat Genet ; 47(2): 164-71, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25581431

RESUMO

Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Ovarianas/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Alelos , Carcinoma Epitelial do Ovário , Feminino , Genes Reporter , Genótipo , Heterozigoto , Humanos , Mutação , Locos de Características Quantitativas , Risco , Adulto Jovem
17.
Eur J Hum Genet ; 23(7): 963-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25335493

RESUMO

Schwannomatosis is characterized by the development of multiple non-vestibular, non-intradermal schwannomas. Constitutional inactivating variants in two genes, SMARCB1 and, very recently, LZTR1, have been reported. We performed exome sequencing of 13 schwannomatosis patients from 11 families without SMARCB1 deleterious variants. We identified four individuals with heterozygous loss-of-function variants in LZTR1. Sequencing of the germline of 60 additional patients identified 18 additional heterozygous variants in LZTR1. We identified LZTR1 variants in 43% and 30% of familial (three of the seven families) and sporadic patients, respectively. In addition, we tested LZTR1 protein immunostaining in 22 tumors from nine unrelated patients with and without LZTR1 deleterious variants. Tumors from individuals with LZTR1 variants lost the protein expression in at least a subset of tumor cells, consistent with a tumor suppressor mechanism. In conclusion, our study demonstrates that molecular analysis of LZTR1 may contribute to the molecular characterization of schwannomatosis patients, in addition to NF2 mutational analysis and the detection of chromosome 22 losses in tumor tissue. It will be especially useful in differentiating schwannomatosis from mosaic Neurofibromatosis type 2 (NF2). However, the role of LZTR1 in the pathogenesis of schwannomatosis needs further elucidation.


Assuntos
Predisposição Genética para Doença/genética , Mutação , Neurilemoma/genética , Neurofibromatoses/genética , Neoplasias Cutâneas/genética , Fatores de Transcrição/genética , Adulto , Idoso , Sequência de Aminoácidos , Exoma/genética , Saúde da Família , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Neurilemoma/metabolismo , Neurofibromatoses/metabolismo , Linhagem , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Neoplasias Cutâneas/metabolismo , Fatores de Transcrição/metabolismo , Adulto Jovem
18.
J Mol Diagn ; 16(4): 393-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24815379

RESUMO

Somatic mosaicism represents the coexistence of two or more cell populations with different genotypes in one person, and it is involved in >30 monogenic disorders. Somatic mosaicism characterizes approximately 25% to 33% of patients with de novo neurofibromatosis type 2 (NF2). The identification of mosaicism is crucial to patients and their families because the clinical course of the disease and its transmission risk is influenced by the degree and distribution of mutated cells. Moreover, in NF2, the capability of discriminating patients with mosaicism is especially important to make differential diagnosis with schwannomatosis. However, the identification of mosaic variants is considerably difficult, and the development of specific molecular techniques to detect low levels of unknown molecular alterations is required. Co-amplification at lower denaturation temperature (COLD)-PCR has been described as a powerful method to selectively amplify minority alleles from mixtures of wild-type and mutation-containing sequences. Here, we applied COLD-PCR to molecular analysis of patients with NF2 mosaicism. With the use of COLD-PCR, followed by direct sequencing, we were able to detect NF2 mutations in blood DNA of three patients with NF2 mosaicism. Our study has shown the capability of COLD-PCR in enriching low-represented mutated allele in blood DNA sample, making it usable for molecular diagnosis of patients with mosaicism.


Assuntos
Análise Mutacional de DNA/métodos , Mosaicismo , Neurofibromatose 2/genética , Neurofibromina 2/genética , Reação em Cadeia da Polimerase/métodos , Temperatura Baixa , Feminino , Genes da Neurofibromatose 2 , Humanos , Neurofibromatose 2/sangue , Neurofibromatose 2/diagnóstico , Neurofibromina 2/sangue , Sensibilidade e Especificidade
19.
Epileptic Disord ; 16(1): 132-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24667735

RESUMO

Neurofibromatosis type 2 (NF2) is a dominantly inherited syndrome caused by mutations of the tumour-suppressor NF2, which encodes the merlin protein. Mutations are associated with a predisposition to development of benign tumours in the central nervous system. Even though cerebral cortical lesions are frequently associated with seizures, epilepsy is rarely described in NF2. Here, we describe an adult case of NF2 in which the onset of symptoms was characterised by status epilepticus. In this patient, we identified the novel c.428_430delCTTdel mutation in NF2, involving the amino-terminal FERM domain, which is fundamental for the correct tumour suppressor function of the protein. Bioinformatic analyses revealed an important structural perturbation of the FERM domain, with a predicted impairment of the anti-tumour activity.


Assuntos
Encéfalo/patologia , Mutação/genética , Neurofibromatose 2/genética , Neurofibromina 2/genética , Medula Espinal/patologia , Estado Epiléptico/genética , Eletroencefalografia/métodos , Humanos , Masculino , Neurofibromina 2/química , Linhagem , Estado Epiléptico/diagnóstico , Adulto Jovem
20.
PLoS One ; 9(2): e86924, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24516540

RESUMO

The identification of founder mutations in cancer predisposing genes is important to improve risk assessment in geographically defined populations, since it may provide specific targets resulting in cost-effective genetic testing. Here, we report the characterization of the BRCA1 c.190T>C (p.Cys64Arg) mutation, mapped to the RING-finger domain coding region, that we detected in 43 hereditary breast/ovarian cancer (HBOC) families, for the large part originating from the province of Bergamo (Northern Italy). Haplotype analysis was performed in 21 families, and led to the identification of a shared haplotype extending over three BRCA1-associated marker loci (0.4 cM). Using the DMLE+2.2 software program and regional population demographic data, we were able to estimate the age of the mutation to vary between 3,100 and 3,350 years old. Functional characterization of the mutation was carried out at both transcript and protein level. Reverse transcriptase-PCR analysis on lymphoblastoid cells revealed expression of full length mRNA from the mutant allele. A green fluorescent protein (GFP)-fragment reassembly assay showed that the p.Cys64Arg substitution prevents the binding of the BRCA1 protein to the interacting protein BARD1, in a similar way as proven deleterious mutations in the RING-domain. Overall, 55 of 83 (66%) female mutation carriers had a diagnosis of breast and/or ovarian cancer. Our observations indicate that the BRCA1 c.190T>C is a pathogenic founder mutation present in the Italian population. Further analyses will evaluate whether screening for this mutation can be suggested as an effective strategy for the rapid identification of at-risk individuals in the Bergamo area.


Assuntos
Proteína BRCA1/química , Proteína BRCA1/genética , Efeito Fundador , Predisposição Genética para Doença , Mutação/genética , Adulto , Fatores Etários , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Segregação de Cromossomos/genética , Éxons/genética , Família , Feminino , Regulação Neoplásica da Expressão Gênica , Geografia , Proteínas de Fluorescência Verde/metabolismo , Haplótipos/genética , Humanos , Itália , Pessoa de Meia-Idade , Taxa de Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Domínios RING Finger , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
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