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1.
Blood ; 132(5): 469-483, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29891534

RESUMO

Chuvash polycythemia is an autosomal recessive form of erythrocytosis associated with a homozygous p.Arg200Trp mutation in the von Hippel-Lindau (VHL) gene. Since this discovery, additional VHL mutations have been identified in patients with congenital erythrocytosis, in a homozygous or compound-heterozygous state. VHL is a major tumor suppressor gene, mutations in which were first described in patients presenting with VHL disease, which is characterized by the development of highly vascularized tumors. Here, we identify a new VHL cryptic exon (termed E1') deep in intron 1 that is naturally expressed in many tissues. More importantly, we identify mutations in E1' in 7 families with erythrocytosis (1 homozygous case and 6 compound-heterozygous cases with a mutation in E1' in addition to a mutation in VHL coding sequences) and in 1 large family with typical VHL disease but without any alteration in the other VHL exons. In this study, we show that the mutations induced a dysregulation of VHL splicing with excessive retention of E1' and were associated with a downregulation of VHL protein expression. In addition, we demonstrate a pathogenic role for synonymous mutations in VHL exon 2 that altered splicing through E2-skipping in 5 families with erythrocytosis or VHL disease. In all the studied cases, the mutations differentially affected splicing, correlating with phenotype severity. This study demonstrates that cryptic exon retention and exon skipping are new VHL alterations and reveals a novel complex splicing regulation of the VHL gene. These findings open new avenues for diagnosis and research regarding the VHL-related hypoxia-signaling pathway.


Assuntos
Éxons , Predisposição Genética para Doença , Mutação , Policitemia/genética , Splicing de RNA , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Doença de von Hippel-Lindau/genética , Adolescente , Adulto , Criança , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Policitemia/classificação , Policitemia/patologia , Adulto Jovem , Doença de von Hippel-Lindau/patologia
2.
J Med Genet ; 55(1): 15-20, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28490613

RESUMO

BACKGROUND: We previously showed that the BRCA1 variant c.5096G>A p.Arg1699Gln (R1699Q) was associated with an intermediate risk of breast cancer (BC) and ovarian cancer (OC). This study aimed to assess these cancer risks for R1699Q carriers in a larger cohort, including follow-up of previously studied families, to further define cancer risks and to propose adjusted clinical management of female BRCA1*R1699Q carriers. METHODS: Data were collected from 129 BRCA1*R1699Q families ascertained internationally by ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) consortium members. A modified segregation analysis was used to calculate BC and OC risks. Relative risks were calculated under both monogenic model and major gene plus polygenic model assumptions. RESULTS: In this cohort the cumulative risk of BC and OC by age 70 years was 20% and 6%, respectively. The relative risk for developing cancer was higher when using a model that included the effects of both the R1699Q variant and a residual polygenic component compared with monogenic model (for BC 3.67 vs 2.83, and for OC 6.41 vs 5.83). CONCLUSION: Our results confirm that BRCA1*R1699Q confers an intermediate risk for BC and OC. Breast surveillance for female carriers based on mammogram annually from age 40 is advised. Bilateral salpingo-oophorectomy should be considered based on family history.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Mutação/genética , Neoplasias Ovarianas/genética , Segregação de Cromossomos , Feminino , Humanos , Fatores de Risco
3.
Breast Cancer Res ; 20(1): 28, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29665859

RESUMO

BACKGROUND: The ataxia telangiectasia mutated (ATM) gene is a moderate-risk breast cancer susceptibility gene; germline loss-of-function variants are found in up to 3% of hereditary breast and ovarian cancer (HBOC) families who undergo genetic testing. So far, no clear histopathological and molecular features of breast tumours occurring in ATM deleterious variant carriers have been described, but identification of an ATM-associated tumour signature may help in patient management. METHODS: To characterise hallmarks of ATM-associated tumours, we performed systematic pathology review of tumours from 21 participants from ataxia-telangiectasia families and 18 participants from HBOC families, as well as copy number profiling on a subset of 23 tumours. Morphology of ATM-associated tumours was compared with that of 599 patients with no BRCA1 and BRCA2 mutations from a hospital-based series, as well as with data from The Cancer Genome Atlas. Absolute copy number and loss of heterozygosity (LOH) profiles were obtained from the OncoScan SNP array. In addition, we performed whole-genome sequencing on four tumours from ATM loss-of-function variant carriers with available frozen material. RESULTS: We found that ATM-associated tumours belong mostly to the luminal B subtype, are tetraploid and show LOH at the ATM locus at 11q22-23. Unlike tumours in which BRCA1 or BRCA2 is inactivated, tumours arising in ATM deleterious variant carriers are not associated with increased large-scale genomic instability as measured by the large-scale state transitions signature. Losses at 13q14.11-q14.3, 17p13.2-p12, 21p11.2-p11.1 and 22q11.23 were observed. Somatic alterations at these loci may therefore represent biomarkers for ATM testing and harbour driver mutations in potentially 'druggable' genes that would allow patients to be directed towards tailored therapeutic strategies. CONCLUSIONS: Although ATM is involved in the DNA damage response, ATM-associated tumours are distinct from BRCA1-associated tumours in terms of morphological characteristics and genomic alterations, and they are also distinguishable from sporadic breast tumours, thus opening up the possibility to identify ATM variant carriers outside the ataxia-telangiectasia disorder and direct them towards effective cancer risk management and therapeutic strategies.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteína BRCA1/genética , Neoplasias da Mama Masculina/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Adulto , Idoso , Ataxia Telangiectasia/complicações , Ataxia Telangiectasia/genética , Ataxia Telangiectasia/patologia , Proteína BRCA2/genética , Neoplasias da Mama/classificação , Neoplasias da Mama/complicações , Neoplasias da Mama/patologia , Neoplasias da Mama Masculina/classificação , Neoplasias da Mama Masculina/complicações , Neoplasias da Mama Masculina/patologia , Dano ao DNA/genética , Reparo do DNA/genética , Feminino , Testes Genéticos , Genômica , Mutação em Linhagem Germinativa/genética , Humanos , Perda de Heterozigosidade/genética , Masculino , Pessoa de Meia-Idade , Deleção de Sequência/genética
4.
Carcinogenesis ; 38(10): 994-1003, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28981872

RESUMO

Recent studies have linked constitutive telomere length (TL) to aging-related diseases including cancer at different sites. ATM participates in the signaling of telomere erosion, and inherited mutations in ATM have been associated with increased risk of cancer, particularly breast cancer. The goal of this study was to investigate whether carriage of an ATM mutation and TL interplay to modify cancer risk in ataxia-telangiectasia (A-T) families.The study population consisted of 284 heterozygous ATM mutation carriers (HetAT) and 174 non-carriers (non-HetAT) from 103 A-T families. Forty-eight HetAT and 14 non-HetAT individuals had cancer, among them 25 HetAT and 6 non-HetAT were diagnosed after blood sample collection. We measured mean TL using a quantitative PCR assay and genotyped seven single-nucleotide polymorphisms (SNPs) recurrently associated with TL in large population-based studies.HetAT individuals were at increased risk of cancer (OR = 2.3, 95%CI = 1.2-4.4, P = 0.01), and particularly of breast cancer for women (OR = 2.9, 95%CI = 1.2-7.1, P = 0.02), in comparison to their non-HetAT relatives. HetAT individuals had longer telomeres than non-HetAT individuals (P = 0.0008) but TL was not associated with cancer risk, and no significant interaction was observed between ATM mutation status and TL. Furthermore, rs9257445 (ZNF311) was associated with TL in HetAT subjects and rs6060627 (BCL2L1) modified cancer risk in HetAT and non-HetAT women.Our findings suggest that carriage of an ATM mutation impacts on the age-related TL shortening and that TL per se is not related to cancer risk in ATM carriers. TL measurement alone is not a good marker for predicting cancer risk in A-T families.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Ataxia Telangiectasia/complicações , Mutação , Neoplasias/genética , Telômero/genética , Ataxia Telangiectasia/genética , Neoplasias da Mama/genética , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Encurtamento do Telômero/genética , Proteína bcl-X/genética
5.
Int Cancer Conf J ; 12(1): 19-23, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36605832

RESUMO

We report the first-ever documented case of successful treatment of paraneoplastic cerebellar degeneration (PCD) with radiotherapy. A 31-year-old female presented with rapidly progressing neurological symptoms, which were revealed to be due to PCD secondary to an undiagnosed breast cancer. The cancer responded well to chemotherapy, but her neurological status continued to deteriorate, eventually progressing to complete expressive aphasia and dyssynergia with paraparesis. Due to the extraordinarily rapid progression of the disorder, a treatment with tumorectomy and radiotherapy of the whole brain was performed. This proved to be very successful, with a complete stop of the deterioration of symptoms after treatment and with a significant neurologic improvement in the following months. This case indicates that there may be a place for radiotherapy in the treatment of PCD. Current treatment options have proven insufficient and no guidelines for treatment currently exist. As such, the disorder remains associated with a very poor prognosis and often entails permanent loss of function. Radiation, with its known immunosuppressive effect and non-stochastic effects on the nervous system at the proper doses, might therefore be a valid option. However, we should note that it was in this instance combined with a removal of the primary tumor and as such, its individual efficacy cannot be considered proven.

6.
J Med Genet ; 48(4): 226-34, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21398687

RESUMO

BACKGROUND: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant disorder predisposing humans to cutaneous and uterine leiomyomas; in 20% of affected families, type 2 papillary renal cell cancers (PRCCII) also occur with aggressive course and poor prognosis. HLRCC results from heterozygous germline mutations in the tumour suppressor fumarate hydratase (FH) gene. METHODS: As part of the French National Cancer Institute (INCa) 'Inherited predispositions to kidney cancer' network, sequence analysis and a functional study of FH were preformed in 56 families with clinically proven or suspected HLRCC and in 23 patients with isolated PRCCII (5 familial and 18 sporadic). RESULTS: The study identified 32 different germline FH mutations (15 missense, 6 frameshifts, 4 nonsense, 1 deletion/insertion, 5 splice site, and 1 complete deletion) in 40/56 (71.4%) families with proven or suspected HLRCC and in 4/23 (17.4%) probands with PRCCII alone, including 2 sporadic cases. 21 of these were novel and all were demonstrated as deleterious by significant reduction of FH enzymatic activity. In addition, 5 asymptomatic parents in 3 families were confirmed as carrying disease-causing mutations. CONCLUSIONS: This study identified and characterised 21 novel FH mutations and demonstrated that PRCCII can be the only one manifestation of HLRCC. Due to the incomplete penetrance of HLRCC, the authors propose to extend the FH mutation analysis to every patient with PRCCII occurring before 40 years of age or when renal tumour harbours characteristic histologic features, in order to discover previously ignored HLRCC affected families.


Assuntos
Carcinoma de Células Renais/genética , Fumarato Hidratase/genética , Neoplasias Renais/genética , Mutação , Adulto , Idoso , Linhagem Celular Tumoral , Códon sem Sentido , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Rearranjo Gênico , Genótipo , Mutação em Linhagem Germinativa , Humanos , Mutação INDEL , Leiomiomatose/congênito , Leiomiomatose/genética , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Síndromes Neoplásicas Hereditárias , Linhagem , Neoplasias Cutâneas , Neoplasias Uterinas
7.
Hum Mutat ; 31(3): E1175-85, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20077502

RESUMO

Fifteen years ago BRCA1 and BRCA2 were reported as high penetrant breast cancer predisposing genes. However, mutations in these genes are found in only a fraction of high risk families. BARD1 is a candidate breast cancer gene, but only a limited number of missense mutations with rather unclear pathogenic consequences have been reported.We screened 196 high risk breast cancer families for the occurrence of BARD1 variants. All genetic variants were analyzed using clinical information as well as IN SILICO predictive tools, including protein modeling. We found three candidate pathogenic mutations in seven families including a first case of a protein truncating mutation (p.Glu652fs) removing the entire second BRCT domain of BARD1. In conclusion, we provide evidence for an increased breast cancer risk associated to specific BARD1 germline mutations. However, these BARD1 mutations occur in a minority of hereditary breast cancer families.


Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Mutação de Sentido Incorreto , Mutação , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Biologia Computacional/métodos , Saúde da Família , Feminino , Variação Genética , Humanos , Masculino , Neoplasias Ovarianas/genética , Linhagem
9.
Br J Cancer ; 99(2): 364-70, 2008 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-18612309

RESUMO

Mutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the CDKN2A locus at 9p21, which encodes two unrelated proteins, p16(INK4a) and p14(ARF). Rare mutations in CDK4 have also been linked to the disease. Although the CDKN2A gene has been shown to be the major melanoma predisposing gene, there remains a significant proportion of melanoma kindreds linked to 9p21 in which germline mutations of CDKN2A have not been identified through direct exon sequencing. The purpose of this study was to assess the contribution of large rearrangements in CDKN2A to the disease in melanoma-prone families using multiplex ligation-dependent probe amplification. We examined 214 patients from independent pedigrees with at least two CMM cases. All had been tested for CDKN2A and CDK4 point mutation, and 47 were found positive. Among the remaining 167 negative patients, one carried a novel genomic deletion of CDKN2A exon 2. Overall, genomic deletions represented 2.1% of total mutations in this series (1 of 48), confirming that they explain a very small proportion of CMM susceptibility. In addition, we excluded a new gene on 9p21, KLHL9, as being a major CMM gene.


Assuntos
Genes p16 , Melanoma/genética , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Proteínas de Transporte/genética , Cromossomos Humanos Par 9 , Inibidor p16 de Quinase Dependente de Ciclina/genética , Éxons , Feminino , Deleção de Genes , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Mutação Puntual , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína Supressora de Tumor p14ARF/genética
10.
Cancer Genet Cytogenet ; 182(1): 40-2, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18328949

RESUMO

Noonan syndrome (NS) is an autosomal dominant disorder characterized by short stature, typical craniofacial dysmorphism, skeletal anomalies, congenital heart defects, and predisposition to malignant tumors. In approximately 50% of cases, the disease is caused by missense mutations in the PTPN11 gene. To date, solid tumors, and particularly brain tumors and rhabdomyosarcomas, have been documented in patients with NS; however, few cases of neuroblastoma associated with NS have been reported. Here we report an unusual case of neuroblastoma with mediastinal, retroperitoneal, and medullar locations associated in a NS patient carrying a PTPN11 germline missense mutation (p.G60A). This missense mutation occurs within the N-SH2 domain of the PTPN11 gene and has been reported to be associated with acute leukemia in NS patients. The association of this p.G60A PTPN11 mutation with neuroblastoma provides new evidence that gain of function PTPN11 mutations may play an important role in the pathogenesis of solid tumors associated with Noonan syndrome.


Assuntos
Neoplasias do Mediastino/genética , Neuroblastoma/complicações , Neuroblastoma/genética , Síndrome de Noonan/complicações , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Neoplasias Retroperitoneais/genética , Anormalidades Múltiplas , Feminino , Mutação em Linhagem Germinativa , Humanos , Lactente , Neoplasias do Mediastino/complicações , Mutação de Sentido Incorreto , Neoplasias Retroperitoneais/complicações
11.
Fam Cancer ; 6(4): 453-61, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17624602

RESUMO

PURPOSE: From epidemiological studies it appears that breast cancer (BC) and cutaneous melanoma (CMM) in the same individual occur at a higher frequency than expected by chance. Genetic factors common to both cancers can be suspected. Our goal was to estimate the involvement of "high risk" genes in patients presenting these two neoplasia, selected irrespectively from family history and age at diagnosis. EXPERIMENTAL DESIGN: Eighty two patients with BC and CMM were screened for BRCA1, BRCA2, TP53, CDKN2A and CDK4 (exon 2) germline mutations. RESULTS: Deleterious mutations were identified in 6 patients: two carriers of a BRCA1 germline mutation, two carriers of TP53 germline mutations (one of which also harbored a BRCA2 deleterious mutation, the other one a BRCA2 unclassified variant), and two carriers of a CDKN2A germline mutation. In addition, 6 variants of unknown signification were identified in BRCA1 or BRCA2 genes. Regarding family history, 3/13 (23%) patients with a positive family history of BC or CMM were carriers of a germline mutation, whereas only 3/69 (4%) patients without family history were carriers of a germline mutation. CONCLUSION: Our findings show that few patients with BC and CMM who lacked family histories of these cancers are carriers of deleterious germline mutations in four of the five genes we examined. We describe for the first time, two simultaneous BRCA2 and TP53 mutations, suggesting that analysis in more than one gene could be performed if a patient's personal or familial history does not match a single syndrome.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Mutação em Linhagem Germinativa/genética , Melanoma/genética , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Quinase 4 Dependente de Ciclina/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Neoplasias Cutâneas/genética
13.
J Dairy Res ; 72 Spec No: 73-80, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16180724

RESUMO

Ataxia-telangiectasia (AT) is a rare autosomal recessive early childhood disorder, characterized by progressive neuronal degeneration, immunological deficiency, radiosensitivity and an increased risk of cancer caused in most cases by mutations in the AT-mutated gene (ATM). Epidemiological studies on AT families have shown that AT heterozygous women have an increased risk of developing breast cancer (BC). The ATM protein plays a central role in the recognition and repair of DNA double-strand breaks and the subsequent activation of cell-cycle checkpoints. Whilst AT is a rare disease, 0.5-1 % of the general population are estimated to be AT mutation carriers, thus any increases in the risks of cancer associated with ATM carrier status are of public health relevance. The main results of our published studies on the risk of BC in 34 French AT families according to heterozygote status, type of ATM mutation and exogenous factors are summarized here. The risk of BC was higher in ATM heterozygous (HetATM) women and did not differ significantly according to the type of ATM mutation (missense vs truncating) carried by the AT family members but appeared associated with the position of some truncating mutations in certain binding domains of the ATM protein. The effect of exogenous factors, such as reproductive life factors and exposure to ionizing radiation, on the risk of BC according to ATM heterozygote status was assessed. There was no evidence for interaction (except for age at first full-term pregnancy). These findings does not appear to justify a separate screening program from that already available to other women with a first-degree relative affected by BC, as their risks have similar amplitude. Chest X-rays did not appear to be a risk factor for BC in our study population. More powerful studies, using data sets pooled from international sources are being set up to confirm these observations.


Assuntos
Ataxia Telangiectasia/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Proteínas Mutadas de Ataxia Telangiectasia , Neoplasias da Mama Masculina/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Feminino , França , Heterozigoto , Humanos , Masculino , Mutação , Proteínas Serina-Treonina Quinases/genética , Fatores de Risco , Proteínas Supressoras de Tumor/genética
14.
Int J Cancer ; 99(4): 619-23, 2002 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11992555

RESUMO

Ataxia-telangiectasia (AT) is a rare autosomal recessive disorder, characterized by progressive neuronal degeneration, immunological deficiency, radio-sensitivity and an increased risk of cancer. Although several studies have confirmed that AT heterozygosis increases the risk of breast cancer (BC), we do not know how exogenous factors affect this risk. We performed an epidemiological study on the cancer risks associated with AT heterozygosis in France and explored the variation in BC risk according to environmental factors, such as reproductive factors and exposure to ionizing radiation. Information on the amount of ionizing radiation received by an individual in their lifetime and on their reproductive life was collected from the living relatives of 34 AT children (175 female relatives). Consistent with previous reports and with our previous estimate on the entire retrospective cohort, we found that the risk of developing BC is 3.6-fold higher among ATM heterozygous women. An increased risk was associated with an early age at menarche, a late age at first childbirth, nulliparity, premenopausal status and increasing periods of breast cell mitotic activity (BCMA) prior to the first childbirth. Age at menarche, age at 1st childbirth and BCMA seemed to have a stronger effect in ATM heterozygotes than in non-ATM heterozygotes. However, the tests were not all statistically significant (only age at 1st childbirth). Surprisingly, the risk of BC decreased when the chest or breasts were irradiated. It is difficult to interpret the data because of the small sample size, but further investigations should provide a biological explanation for the variation in BC risk associated with exogenous factors according to ATM heterozygosis status.


Assuntos
Neoplasias da Mama/genética , Heterozigoto , Proteínas Serina-Treonina Quinases/genética , Adolescente , Adulto , Idoso , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Meio Ambiente , Feminino , Humanos , Trabalho de Parto , Menarca , Pessoa de Meia-Idade , Gravidez , Fatores de Risco , Fatores de Tempo , Proteínas Supressoras de Tumor
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