Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 107
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Med Genet ; 56(5): 308-316, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30819809

RESUMO

BACKGROUND: Ataxia telangiectasia (A-T) is a neurodegenerative disorder. While patients with classic A-T generally die in their 20s, some patients with variant A-T, who have residual ataxia-telangiectasia mutated (ATM) kinase activity, have a milder phenotype. We noticed two commonly occurring ATM mutations that appeared to be associated with prolonged survival and decided to study patients carrying one of these mutations. METHODS: Data were retrospectively collected from the Dutch, Italian, German and French A-T cohorts. To supplement these data, we searched the literature for patients with identical genotypes. RESULTS: This study included 35 patients who were homozygous or compound heterozygous for the ATM c.3576G>A; p.(Ser1135_Lys1192del58) mutation and 24 patients who were compound heterozygous for the ATM c.8147T>C; p.(Val2716Ala) mutation. Compared with 51 patients with classic A-T from the Dutch cohort, patients with ATM c.3576G>A had a longer survival and were less likely to develop cancer, respiratory disease or immunodeficiency. This was also true for patients with ATM c.8147T>C, who additionally became wheelchair users later in life and had fewer telangiectasias. The oldest patient with A-T reported so far was a 78-year-old patient who was compound heterozygous for ATM c.8147T>C. ATM kinase activity was demonstrated in cells from all patients tested with the ATM c.8147T>C mutant protein and only at a low level in some patients with ATM c.3576G>A. CONCLUSION: Compared with classic A-T, the presence of ATM c.3576G>A results in a milder classic phenotype. Patients with ATM c.8147T>C have a variant phenotype with prolonged survival, which in exceptional cases may approach a near-normal lifespan.

2.
Cancer Cell ; 35(2): 256-266.e5, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30753826

RESUMO

Biallelic germline mutations affecting NTHL1 predispose carriers to adenomatous polyposis and colorectal cancer, but the complete phenotype is unknown. We describe 29 individuals carrying biallelic germline NTHL1 mutations from 17 families, of which 26 developed one (n = 10) or multiple (n = 16) malignancies in 14 different tissues. An unexpected high breast cancer incidence was observed in female carriers (60%). Mutational signature analysis of 14 tumors from 7 organs revealed that NTHL1 deficiency underlies the main mutational process in all but one of the tumors (93%). These results reveal NTHL1 as a multi-tumor predisposition gene with a high lifetime risk for extracolonic cancers and a typical mutational signature observed across tumor types, which can assist in the recognition of this syndrome.

3.
Sci Rep ; 8(1): 16719, 2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30425284

RESUMO

In hyper-IgE syndromes (HIES), a group of primary immunodeficiencies clinically overlapping with atopic dermatitis, early diagnosis is crucial to initiate appropriate therapy and prevent irreversible complications. Identification of underlying gene defects such as in DOCK8 and STAT3 and corresponding molecular testing has improved diagnosis. Yet, in a child and her newborn sibling with HIES phenotype molecular diagnosis was misleading. Extensive analyses driven by the clinical phenotype identified an intronic homozygous DOCK8 variant c.4626 + 76 A > G creating a novel splice site as disease-causing. While the affected newborn carrying the homozygous variant had no expression of DOCK8 protein, in the index patient molecular diagnosis was compromised due to expression of altered and wildtype DOCK8 transcripts and DOCK8 protein as well as defective STAT3 signaling. Sanger sequencing of lymphocyte subsets revealed that somatic alterations and reversions revoked the predominance of the novel over the canonical splice site in the index patient explaining DOCK8 protein expression, whereas defective STAT3 responses in the index patient were explained by a T cell phenotype skewed towards central and effector memory T cells. Hence, somatic alterations and skewed immune cell phenotypes due to selective pressure may compromise molecular diagnosis and need to be considered with unexpected clinical and molecular findings.

4.
Immun Inflamm Dis ; 6(4): 428-434, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30028084

RESUMO

INTRODUCTION: Dickkopf-1 (DKK1) is a soluble protein and antagonist of the Wnt/ß-catenin signaling pathway. DKK1 is found elevated in serum from patients affected with various types of cancers and in some instances, it is considered a diagnostic and prognostic biomarker. Elevated serum levels of DKK1 have also been detected in animal models of chronic inflammatory diseases. Previous work from our laboratory has demonstrated upregulation of DKK1 in cells and mouse models of the bone marrow failure (BMF) and cancer-prone disease Fanconi anemia (FA). The present study aimed to investigate whether DKK1 blood levels in patients are associated with FA or inflammatory responses to acute infections. METHODS: Plasma samples were collected from 58 children admitted to the Centre Mère-Enfant Soleil du Centre Hospitalier de Québec-Université Laval with signs of acute infections. Blood plasma specimens were also collected from healthy blood donors at the Héma-Québec blood donor clinic. Plasmas from patients diagnosed with FA were also included in the study. DKK1 levels in blood plasmas were assessed by standard ELISA. RESULTS: Patients with acute infections showed dramatically high levels of DKK1 (6072 ± 518 pg/ml) in their blood compared to healthy blood donors (1726 ± 95 pg/ml). No correlations were found between DKK1 levels and C reactive protein (CRP) concentration, platelet numbers, or white blood cell counts. Patients with FA showed higher DKK1 plasma levels (3419 ± 147.5 pg/ml) than healthy blood donors (1726 ± 95 pg/ml) but significantly lower than patients with acute infections. CONCLUSION: These findings suggest that blood DKK1 is elevated in response to infections and perhaps to inflammatory responses.

5.
Eur J Hum Genet ; 26(9): 1282-1287, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29760432

RESUMO

Recently, variants in DONSON have been reported to cause different disorders of the microcephalic primordial dwarfism spectrum. Using whole-exome sequencing, we identified two novel, compound heterozygous DONSON variants in a pair of siblings, one of whom was previously diagnosed with Fanconi anemia. This occurred because the present cases exhibited clinical findings in addition to those of the microcephalic primordial dwarfism disorder, including severe limb malformations. These findings suggest that the DONSON and Fanconi anemia proteins could have supplementary roles in developmental processes as they have in the maintenance of genomic integrity, resulting in related disease phenotypes.

6.
Pediatr Nephrol ; 33(9): 1547-1551, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29651604

RESUMO

BACKGROUND: Fanconi anaemia (FA) is an inherited disease with bone marrow failure, variable congenital and developmental abnormalities, and cancer predisposition. With improved survival, non-haematological manifestations of FA become increasingly important for long-term management. While renal abnormalities are recognized, detailed data on patterns and frequency and implications for long-term management are sparse. METHODS: We reviewed clinical course and imaging findings of FA patients with respect to renal complications in our centre over a 25-year period to formulate some practical suggestions for guidelines for management of renal problems associated with FA. RESULTS: Thirty patients including four sibling sets were reviewed. On imaging, 14 had evidence of anatomical abnormalities of the kidneys. Two cases with severe phenotype, including renal abnormalities, had chronic kidney disease (CKD) at diagnosis. Haematopoietic stem cell transplantation was complicated by significant acute kidney injury (AKI) in three cases. In three patients, there was CKD at long-term follow-up. All patients had normal blood pressure. CONCLUSIONS: Evaluation of renal anatomy with ultrasound imaging is important at diagnostic workup of FA. While CKD is uncommon at diagnosis, our data suggests that the incidence of CKD increases with age, in particular after haematopoietic stem cell transplantation. Monitoring of renal function is essential for management of FA. Based on these long-term clinical observations, we formulate some practical guidelines for assessment and management of renal abnormalities in FA.

7.
Nat Commun ; 9(1): 967, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511213

RESUMO

BRCA1 is a tumor suppressor that regulates DNA repair by homologous recombination. Germline mutations in BRCA1 are associated with increased risk of breast and ovarian cancer and BRCA1 deficient tumors are exquisitely sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. Therefore, uncovering additional components of this DNA repair pathway is of extreme importance for further understanding cancer development and therapeutic vulnerabilities. Here, we identify EDC4, a known component of processing-bodies and regulator of mRNA decapping, as a member of the BRCA1-BRIP1-TOPBP1 complex. EDC4 plays a key role in homologous recombination by stimulating end resection at double-strand breaks. EDC4 deficiency leads to genome instability and hypersensitivity to DNA interstrand cross-linking drugs and PARP inhibitors. Lack-of-function mutations in EDC4 were detected in BRCA1/2-mutation-negative breast cancer cases, suggesting a role in breast cancer susceptibility. Collectively, this study recognizes EDC4 with a dual role in decapping and DNA repair whose inactivation phenocopies BRCA1 deficiency.


Assuntos
Proteína BRCA1/metabolismo , Neoplasias da Mama/metabolismo , Reparo do DNA , Proteínas/metabolismo , Proteína BRCA1/genética , Neoplasias da Mama/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Recombinação Homóloga , Humanos , Mutação , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ligação Proteica , Proteínas/genética , Capuzes de RNA/genética , Capuzes de RNA/metabolismo
8.
BMC Med Genet ; 19(1): 7, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29325523

RESUMO

BACKGROUND: Fanconi anemia (FA) is an inherited genomic instability disorder with congenital and developmental abnormalities, bone marrow failure and predisposition to cancer early in life, and cellular sensitivity to DNA interstrand crosslinks. CASE PRESENTATION: A fifty-one-year old female patient, initially diagnosed with FA in childhood on the basis of classic features and increased chromosomal breakage, and remarkable sun-sensitivity is described. She only ever had mild haematological abnormalities and no history of malignancy. To identify and characterise the genetic defect in this lady, who is one of the oldest reported FA patients, we used whole-exome sequencing for identification of causative mutations, and functionally characterized the cellular phenotype. Detection of the novel splice site mutation c.793-2A > G and the previously described missense mutation c.1765C > T (p.Arg589Trp) in XPF/ERCC4/FANCQ assign her as the third individual of complementation group FA-Q. Ectopic expression of wildtype, but not mutant, XPF/ERCC4/FANCQ, in patient-derived fibroblasts rescued cellular resistance to DNA interstrand-crosslinking agents. Patient derived FA-Q cells showed impaired nuclear excision repair capacity. However, mutated XPF/ERCC4/FANCQ protein in our patient's cells, as in the two other patients with FA-Q, was detectable on chromatin, in contrast to XP-F cells, where missense-mutant protein failed to properly translocate to the nucleus. CONCLUSIONS: Patients with FA characteristics and UV sensitivity should be tested for mutations in XPF/ERCC4/FANCQ. The missense mutation p.Arg589Trp was previously detected in patients diagnosed with Xeroderma pigmentosum or Cockayne syndrome. Hence, phenotypic manifestations associated with this XPF/ERCC4/ FANCQ mutation are highly variable.

9.
Klin Padiatr ; 229(6): 329-334, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29132164

RESUMO

Individuals with Fanconi anemia (FA) have a high risk of developing myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), yet the secondary somatic mutations lending to these malignancies remain to be further elucidated. We employed a next-generation sequencing myeloid neoplasia gene panel to determine the mutational spectrum of FA-related MDS/AML. Ten of 16 patients showed missense, nonsense, insertion or duplication mutations in 13 genes. In contrast to findings in MDS in the general population, mutations in genes involved in RNA splicing were rarely affected. Mutations in RUNX1 and genes of the RAS pathway appeared more instrumental in the pathogenesis of FA myeloid malignancies. RUNX1 mutations were associated with more advanced disease. Interestingly, one patient with refractory anemia with ring sideroblasts harbored the SF3B1 p.K700E mutation highlighting the mutation's causative role in MDS with ring sideroblasts even in the context of FA. On the whole, our findings implicate a different genetic architecture of FA MDS/AML from adult sporadic MDS. Notably, the genetic events resemble those described in pediatric MDS.

11.
J Clin Invest ; 127(8): 3013-3027, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28691929

RESUMO

The WD40-containing E3 ubiquitin ligase RFWD3 has been recently linked to the repair of DNA damage by homologous recombination (HR). Here we have shown that an RFWD3 mutation within the WD40 domain is connected to the genetic disease Fanconi anemia (FA). An individual presented with congenital abnormalities characteristic of FA. Cells from the patient carrying the compound heterozygous mutations c.205_206dupCC and c.1916T>A in RFWD3 showed increased sensitivity to DNA interstrand cross-linking agents in terms of increased chromosomal breakage, reduced survival, and cell cycle arrest in G2 phase. The cellular phenotype was mirrored in genetically engineered human and avian cells by inactivation of RFWD3 or introduction of the patient-derived missense mutation, and the phenotype was rescued by expression of wild-type RFWD3 protein. HR was disrupted in RFWD3-mutant cells as a result of impaired relocation of mutant RFWD3 to chromatin and defective physical interaction with replication protein A. Rfwd3 knockout mice appear to have increased embryonic lethality, are subfertile, show ovarian and testicular atrophy, and have a reduced lifespan resembling that of other FA mouse models. Although RFWD3 mutations have thus far been detected in a single child with FA, we propose RFWD3 as an FA gene, FANCW, supported by cellular paradigm systems and an animal model.


Assuntos
Anemia de Fanconi/genética , Mutação , Ubiquitina-Proteína Ligases/genética , Alelos , Animais , Ciclo Celular , Linhagem Celular Tumoral , Criança , Dano ao DNA , Reparo do DNA , Exoma , Anemia de Fanconi/metabolismo , Feminino , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação de Sentido Incorreto , Proteínas Nucleares/genética , Fenótipo , Interferência de RNA , Recombinação Genética , Ubiquitina-Proteína Ligases/metabolismo
12.
Mol Cell ; 66(5): 610-621.e4, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28575657

RESUMO

Defects in the repair of DNA interstrand crosslinks (ICLs) are associated with the genome instability syndrome Fanconi anemia (FA). Here we report that cells with mutations in RFWD3, an E3 ubiquitin ligase that interacts with and ubiquitylates replication protein A (RPA), show profound defects in ICL repair. An amino acid substitution in the WD40 repeats of RFWD3 (I639K) found in a new FA subtype abolishes interaction of RFWD3 with RPA, thereby preventing RFWD3 recruitment to sites of ICL-induced replication fork stalling. Moreover, single point mutations in the RPA32 subunit of RPA that abolish interaction with RFWD3 also inhibit ICL repair, demonstrating that RPA-mediated RFWD3 recruitment to stalled replication forks is important for ICL repair. We also report that unloading of RPA from sites of ICL induction is perturbed in RFWD3-deficient cells. These data reveal important roles for RFWD3 localization in protecting genome stability and preserving human health.


Assuntos
Dano ao DNA , Anemia de Fanconi/enzimologia , Reparo de DNA por Recombinação , Origem de Replicação , Proteína de Replicação A/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Sítios de Ligação , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Anemia de Fanconi/genética , Células HeLa , Humanos , Mutação , Ligação Proteica , Interferência de RNA , Proteína de Replicação A/genética , Transfecção , Ubiquitina-Proteína Ligases/genética
13.
Mol Cell ; 66(5): 622-634.e8, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28575658

RESUMO

RFWD3 is a recently identified Fanconi anemia protein FANCW whose E3 ligase activity toward RPA is essential in homologous recombination (HR) repair. However, how RPA ubiquitination promotes HR remained unknown. Here, we identified RAD51, the central HR protein, as another target of RFWD3. We show that RFWD3 polyubiquitinates both RPA and RAD51 in vitro and in vivo. Phosphorylation by ATR and ATM kinases is required for this activity in vivo. RFWD3 inhibits persistent mitomycin C (MMC)-induced RAD51 and RPA foci by promoting VCP/p97-mediated protein dynamics and subsequent degradation. Furthermore, MMC-induced chromatin loading of MCM8 and RAD54 is defective in cells with inactivated RFWD3 or expressing a ubiquitination-deficient mutant RAD51. Collectively, our data reveal a mechanism that facilitates timely removal of RPA and RAD51 from DNA damage sites, which is crucial for progression to the late-phase HR and suppression of the FA phenotype.


Assuntos
Cromatina/enzimologia , Dano ao DNA , DNA/metabolismo , Anemia de Fanconi/enzimologia , Rad51 Recombinase/metabolismo , Reparo de DNA por Recombinação , Proteína de Replicação A/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Cromatina/efeitos dos fármacos , Cromatina/genética , Cromatina/efeitos da radiação , DNA/genética , Anemia de Fanconi/genética , Humanos , Proteínas de Manutenção de Minicromossomo/metabolismo , Mitomicina/farmacologia , Mutação , Fosforilação , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Interferência de RNA , Rad51 Recombinase/genética , Reparo de DNA por Recombinação/efeitos dos fármacos , Reparo de DNA por Recombinação/efeitos da radiação , Proteína de Replicação A/genética , Transfecção , Ubiquitina-Proteína Ligases/genética , Proteína com Valosina
14.
PLoS One ; 12(5): e0177442, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28489894

RESUMO

Epigenetic alterations may contribute to the generation of cancer cells in a multi-step process of tumorigenesis following irradiation of normal body cells. Primary human fibroblasts with intact cell cycle checkpoints were used as a model to test whether X-ray irradiation with 2 and 4 Gray induces direct epigenetic effects (within the first cell cycle) in the exposed cells. ELISA-based fluorometric assays were consistent with slightly reduced global DNA methylation and hydroxymethylation, however the observed between-group differences were usually not significant. Similarly, bisulfite pyrosequencing of interspersed LINE-1 repeats and centromeric α-satellite DNA did not detect significant methylation differences between irradiated and non-irradiated cultures. Methylation of interspersed ALU repeats appeared to be slightly increased (one percentage point; p = 0.01) at 6 h after irradiation with 4 Gy. Single-cell analysis showed comparable variations in repeat methylation among individual cells in both irradiated and control cultures. Radiation-induced changes in global repeat methylation, if any, were much smaller than methylation variation between different fibroblast strains. Interestingly, α-satellite DNA methylation positively correlated with gestational age. Finally, 450K methylation arrays mainly targeting genes and CpG islands were used for global DNA methylation analysis. There were no detectable methylation differences in genic (promoter, 5' UTR, first exon, gene body, 3' UTR) and intergenic regions between irradiated and control fibroblast cultures. Although we cannot exclude minor effects, i.e. on individual CpG sites, collectively our data suggest that global DNA methylation remains rather stable in irradiated normal body cells in the early phase of DNA damage response.


Assuntos
Metilação de DNA/efeitos da radiação , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Células Cultivadas , Dano ao DNA/efeitos da radiação , Epigênese Genética/efeitos da radiação , Fibroblastos/citologia , Humanos , Elementos Nucleotídeos Longos e Dispersos/efeitos dos fármacos , Análise de Célula Única , Raios X
15.
Front Immunol ; 8: 449, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28507545

RESUMO

Typical features of dyskeratosis congenita (DC) resulting from excessive telomere shortening include bone marrow failure (BMF), mucosal fragility, and pulmonary or liver fibrosis. In more severe cases, immune deficiency and recurring infections can add to disease severity. RTEL1 deficiency has recently been described as a major genetic etiology, but the molecular basis and clinical consequences of RTEL1-associated DC are incompletely characterized. We report our observations in a cohort of six patients: five with novel biallelic RTEL1 mutations p.Trp456Cys, p.Ile425Thr, p.Cys1244ProfsX17, p.Pro884_Gln885ins53X13, and one with novel heterozygous mutation p.Val796AlafsX4. The most unifying features were hypocellular BMF in 6/6 and B-/NK-cell lymphopenia in 5/6 patients. In addition, three patients with homozygous mutations p.Trp456Cys or p.Ile425Thr also suffered from immunodeficiency, cerebellar hypoplasia, and enteropathy, consistent with Hoyeraal-Hreidarsson syndrome. Chromosomal breakage resembling a homologous recombination defect was detected in patient-derived fibroblasts but not in hematopoietic compartment. Notably, in both cellular compartments, differential expression of 1243aa and 1219/1300aa RTEL1 isoforms was observed. In fibroblasts, response to ionizing irradiation and non-homologous end joining were not impaired. Telomeric circles did not accumulate in patient-derived primary cells and lymphoblastoid cell lines, implying alternative pathomechanisms for telomeric loss. Overall, RTEL1-deficient cells exhibited a phenotype of replicative exhaustion, spontaneous apoptosis and senescence. Specifically, CD34+ cells failed to expand in vitro, B-cell development was compromised, and T-cells did not proliferate in long-term culture. Finally, we report on the natural history and outcome of our patients. While two patients died from infections, hematopoietic stem cell transplantation (HSCT) resulted in sustained engraftment in two patients. Whether chemotherapy negatively impacts on the course and onset of other DC-related symptoms remains open at present. Early-onset lung disease occurred in one of our patients after HSCT. In conclusion, RTEL deficiency can show a heterogeneous clinical picture ranging from mild hypocellular BMF with B/NK cell lymphopenia to early-onset, very severe, and rapidly progressing cellular deficiency.

16.
PLoS Genet ; 13(4): e1006746, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28453519

RESUMO

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.


Assuntos
Movimento Celular/genética , Mutação da Fase de Leitura/genética , Deficiência Intelectual/genética , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Animais , Citoesqueleto/genética , Exoma/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/patologia , Imagem por Ressonância Magnética , Masculino , Mesencéfalo/diagnóstico por imagem , Mesencéfalo/patologia , Camundongos , Linhagem , Rombencéfalo/diagnóstico por imagem , Rombencéfalo/patologia , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/genética
17.
Hum Mutat ; 38(1): 7-15, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27667302

RESUMO

Werner syndrome (WS) is a rare autosomal recessive disorder characterized by a constellation of adult onset phenotypes consistent with an acceleration of intrinsic biological aging. It is caused by pathogenic variants in the WRN gene, which encodes a multifunctional nuclear protein with exonuclease and helicase activities. WRN protein is thought to be involved in optimization of various aspects of DNA metabolism, including DNA repair, recombination, replication, and transcription. In this update, we summarize a total of 83 different WRN mutations, including eight previously unpublished mutations identified by the International Registry of Werner Syndrome (Seattle, WA) and the Japanese Werner Consortium (Chiba, Japan), as well as 75 mutations already reported in the literature. The Seattle International Registry recruits patients from all over the world to investigate genetic causes of a wide variety of progeroid syndromes in order to contribute to the knowledge of basic mechanisms of human aging. Given the unusually high prevalence of WS patients and heterozygous carriers in Japan, the major goal of the Japanese Consortium is to develop effective therapies and to establish management guidelines for WS patients in Japan and elsewhere. This review will also discuss potential translational approaches to this disorder, including those currently under investigation.


Assuntos
Mutação , Helicase da Síndrome de Werner/genética , Síndrome de Werner/genética , Fatores Etários , Animais , Bases de Dados Genéticas , Modelos Animais de Doenças , Éxons , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Geografia , Humanos , Japão , Camundongos , Fenótipo , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Sistema de Registros , Pesquisa Médica Translacional , Navegador , Síndrome de Werner/diagnóstico , Síndrome de Werner/epidemiologia
19.
Blood Adv ; 1(5): 319-329, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29296947

RESUMO

Detectable clonal mosaicism for large chromosomal events has been associated with aging and an increased risk of hematological and some solid cancers. We hypothesized that genetic cancer predisposition disorders, such as Fanconi anemia (FA), could manifest a high rate of chromosomal mosaic events (CMEs) in peripheral blood, which could be used as early biomarkers of cancer risk. We studied the prevalence of CMEs by single-nucleotide polymorphism (SNP) array in 130 FA patients' blood DNA and their impact on cancer risk. We detected 51 CMEs (4.4-159 Mb in size) in 16 out of 130 patients (12.3%), of which 9 had multiple CMEs. The most frequent events were gains at 3q (n = 6) and 1q (n = 5), both previously associated with leukemia, as well as rearrangements with breakpoint clustering within the major histocompatibility complex locus (P = 7.3 × 10-9). Compared with 15 743 age-matched population controls, FA patients had a 126 to 140 times higher risk of detectable CMEs in blood (P < 2.2 × 10-16). Prevalent and incident hematologic and solid cancers were more common in CME carriers (odds ratio [OR] = 11.6, 95% confidence interval [CI] = 3.4-39.3, P = 2.8 × 10-5), leading to poorer prognosis. The age-adjusted hazard risk (HR) of having cancer was almost 5 times higher in FA individuals with CMEs than in those without CMEs. Regarding survival, the HR of dying was 4 times higher in FA individuals having CMEs (HR = 4.0, 95% CI = 2.0-7.9, P = 5.7 × 10-5). Therefore, our data suggest that molecular karyotyping with SNP arrays in easy-to-obtain blood samples could be used for better monitoring of bone marrow clonal events, cancer risk, and overall survival of FA patients.

20.
Pediatr Hematol Oncol ; 33(1): 5-12, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26900943

RESUMO

A substantial number of individuals with Fanconi anemia (FA) develop bone marrow failure and are treated with androgen therapy in order to increase blood counts. The authors retrospectively identified 70 patients who received androgen therapy any time between July 1976 and September 2014. Among these patients, 37 had medical records for analysis. Twenty-five of the 37 (68%) patients had response in hemoglobin level (n = 25), platelet count (n = 21), and/or absolute neutrophil count (n = 13). The median rise in hemoglobin was 6.5 mg/dL, platelet count 70,000/mm(3), and absolute neutrophil count (ANC) 1530/µL. The majority of patients (n = 22) had a response in 2 or more blood parameters. Reasons for discontinuation of therapy included development of cytogenetic aberrations (n = 9), lack of response (n = 7), hepatic adenoma (n = 6), progression to myelodysplastic syndrome/acute myeloid leukemia (n = 3), stabilization of blood parameters (n = 3), resolution of cytopenia secondary to mosaicism (n = 1), virilization (n = 1), development of anogenital carcinoma (n = 1), inaccessibility of medication (n = 1), and unknown (n = 1). Four patients at last follow-up remain on androgen therapy. These results highlight that androgen therapy can significantly improve blood counts for many FA patients, but progression of underlying bone marrow disease and development of liver adenomas requires careful monitoring.


Assuntos
Androgênios , Adenoma/sangue , Adenoma/mortalidade , Adolescente , Adulto , Androgênios/efeitos adversos , Androgênios/uso terapêutico , Criança , Pré-Escolar , Anemia de Fanconi/sangue , Anemia de Fanconi/tratamento farmacológico , Anemia de Fanconi/mortalidade , Feminino , Alemanha/epidemiologia , Hemoglobinas/metabolismo , Humanos , Contagem de Leucócitos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Masculino , Segunda Neoplasia Primária/sangue , Segunda Neoplasia Primária/mortalidade , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA