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1.
Ann Intern Med ; 173(12): 989-1001, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-32894695

RESUMO

DESCRIPTION: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications. METHODS: The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved. RECOMMENDATIONS: The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.


Assuntos
Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/terapia , Anemia/etiologia , Anemia/terapia , Malformações Arteriovenosas/etiologia , Malformações Arteriovenosas/terapia , Criança , Epistaxe/etiologia , Epistaxe/terapia , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/terapia , Doenças Genéticas Inatas/etiologia , Doenças Genéticas Inatas/terapia , Humanos , Fígado/irrigação sanguínea , Telangiectasia Hemorrágica Hereditária/complicações
2.
Genet Med ; 20(12): 1575-1582, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29565421

RESUMO

PURPOSE: BRCA1/BRCA2 predictive test negatives are proven noncarriers of a BRCA1/BRCA2 mutation that is carried by their relatives. The risk of developing breast cancer (BC) or epithelial ovarian cancer (EOC) in these women is uncertain. The study aimed to estimate risks of invasive BC and EOC in a large cohort of BRCA1/BRCA2 predictive test negatives. METHODS: We used cohort analysis to estimate incidences, cumulative risks, and standardized incidence ratios (SIRs). RESULTS: A total of 1,895 unaffected women were eligible for inclusion in the BC risk analysis and 1,736 in the EOC risk analysis. There were 23 incident invasive BCs and 2 EOCs. The cumulative risk of invasive BC was 9.4% (95% confidence interval (CI) 5.9-15%) by age 85 years and the corresponding risk of EOC was 0.6% (95% CI 0.2-2.6%). The SIR for invasive BC was 0.93 (95% CI 0.62-1.40) in the overall cohort, 0.85 (95% CI 0.48-1.50) in noncarriers from BRCA1 families, and 1.03 (95% CI 0.57-1.87) in noncarriers from BRCA2 families. The SIR for EOC was 0.79 (95% CI 0.20-3.17) in the overall cohort. CONCLUSION: Our results did not provide evidence for elevated risks of invasive BC or EOC in BRCA1/BRCA2 predictive test negatives.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/epidemiologia , Medição de Risco , Fatores de Risco
3.
Hum Mol Genet ; 24(18): 5079-92, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26082470

RESUMO

The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca(2+) o) homeostasis. To elucidate the role of AP2σ2 in Ca(2+) o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype-phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype-phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.


Assuntos
Complexo 2 de Proteínas Adaptadoras/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/genética , Códon , Genes Dominantes , Estudos de Associação Genética , Hipercalcemia/congênito , Mutação , Complexo 2 de Proteínas Adaptadoras/química , Subunidades sigma do Complexo de Proteínas Adaptadoras/química , Adolescente , Adulto , Substituição de Aminoácidos , Biomarcadores , Linhagem Celular , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Expressão Gênica , Humanos , Hipercalcemia/diagnóstico , Hipercalcemia/genética , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Linhagem , Fenótipo , Conformação Proteica , Relação Estrutura-Atividade , Adulto Jovem
4.
Nat Genet ; 39(8): 989-94, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17618283

RESUMO

Using a multistage genetic association approach comprising 7,480 affected individuals and 7,779 controls, we identified markers in chromosomal region 8q24 associated with colorectal cancer. In stage 1, we genotyped 99,632 SNPs in 1,257 affected individuals and 1,336 controls from Ontario. In stages 2-4, we performed serial replication studies using 4,024 affected individuals and 4,042 controls from Seattle, Newfoundland and Scotland. We identified one locus on chromosome 8q24 and another on 9p24 having combined odds ratios (OR) for stages 1-4 of 1.18 (trend; P = 1.41 x 10(-8)) and 1.14 (trend; P = 1.32 x 10(-5)), respectively. Additional analyses in 2,199 affected individuals and 2,401 controls from France and Europe supported the association at the 8q24 locus (OR = 1.16, trend; 95% confidence interval (c.i.): 1.07-1.26; P = 5.05 x 10(-4)). A summary across all seven studies at the 8q24 locus was highly significant (OR = 1.17, c.i.: 1.12-1.23; P = 3.16 x 10(-11)). This locus has also been implicated in prostate cancer.


Assuntos
Cromossomos Humanos Par 8 , Neoplasias Colorretais/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Estudos de Casos e Controles , Mapeamento Cromossômico , Humanos , Desequilíbrio de Ligação , Pessoa de Meia-Idade
5.
Nat Genet ; 39(9): 1127-33, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17704778

RESUMO

Nonsense-mediated mRNA decay (NMD) is of universal biological significance. It has emerged as an important global RNA, DNA and translation regulatory pathway. By systematically sequencing 737 genes (annotated in the Vertebrate Genome Annotation database) on the human X chromosome in 250 families with X-linked mental retardation, we identified mutations in the UPF3 regulator of nonsense transcripts homolog B (yeast) (UPF3B) leading to protein truncations in three families: two with the Lujan-Fryns phenotype and one with the FG phenotype. We also identified a missense mutation in another family with nonsyndromic mental retardation. Three mutations lead to the introduction of a premature termination codon and subsequent NMD of mutant UPF3B mRNA. Protein blot analysis using lymphoblastoid cell lines from affected individuals showed an absence of the UPF3B protein in two families. The UPF3B protein is an important component of the NMD surveillance machinery. Our results directly implicate abnormalities of NMD in human disease and suggest at least partial redundancy of NMD pathways.


Assuntos
Deficiência Intelectual Ligada ao Cromossomo X/genética , Mutação , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Sequência de Aminoácidos , Linhagem Celular Transformada , Códon sem Sentido , Análise Mutacional de DNA , Saúde da Família , Feminino , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Masculino , Deficiência Intelectual Ligada ao Cromossomo X/patologia , Dados de Sequência Molecular , Linhagem , Estabilidade de RNA , RNA Mensageiro/genética , Proteínas de Ligação a RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Síndrome
6.
BMC Cancer ; 12: 487, 2012 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-23088590

RESUMO

BACKGROUND: In Scotland colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer death. Epidemiological studies have reported conflicting associations between statins and CRC risk and there is one published report of the association between statins and CRC survival. METHODS: Analysis was carried out on 309 cases and 294 controls from the Scottish Study of Colorectal Cancer (SOCCS). Cox's hazard and logistic regression models were applied to investigate the association between statin use and CRC risk and survival. RESULTS: In an adjusted logistic regression model, statins were found to show a statistically significant association for three of the four statin variables and were found to not show a statistically significant association with either all-cause or CRC-specific mortality (OR 0.49; 95%CI 0.49-1.36; p-value = 0.17 and OR 0.33; 95%CI 0.08-1.35; P-value = 0.12, respectively). CONCLUSION: We did find a statistically significant association between statin intake and CRC risk but not statin intake and CRC-specific mortality. However, the study was insufficiently powered and larger scale studies may be advisable.


Assuntos
Neoplasias Colorretais/epidemiologia , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Estudos de Casos e Controles , Neoplasias Colorretais/mortalidade , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Risco , Escócia/epidemiologia
7.
J Nutr ; 141(8): 1535-42, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21697298

RESUMO

Vitamin D deficiency has recently been implicated as a possible risk factor in the etiology of numerous diseases, including nonskeletal conditions. In humans, skin synthesis following exposure to UVB is a potent source of vitamin D, but in regions with low UVB, individuals are at risk of vitamin D deficiency. Our objectives were to describe the prevalence of vitamin D deficiency and to investigate determinants of plasma 25-hydroxyvitamin D (25-OHD) concentrations in a high northern latitude country. Detailed dietary, lifestyle, and demographic data were collected for 2235 healthy adults (21-82 y) from Scotland. Plasma 25-OHD was measured by liquid chromatography-tandem MS. Among study participants, 34.5% were severely deficient (25-OHD <25 nmol/L) and 28.9% were at high risk of deficiency (25-40 nmol/L). Only 36.6% of participants were at low risk of vitamin D deficiency or had adequate levels (>40 nmol/L). Among participants who were taking supplements, 21.3% had a May-standardized 25-OHD concentration >50 nmol/L, 54.2% had 25-50 nmol/L, and 24.5% had <25 nmol/L, whereas this was 15.6, 43.3, and 41%, respectively, among those who did not take supplements (P < 0.0001). The most important sources of vitamin D were supplements and fish consumption. Vitamin D deficiency in Scotland is highly prevalent due to a combination of insufficient exposure to UVB and insufficient dietary intake. Higher dietary vitamin D intake modestly improved the plasma 25-OHD concentration (P = 0.02) and reduced the proportion of severely deficient individuals (P < 0.0001). In regions with low UVB exposure, dietary and supplement intake may be much more important than previously thought and consideration should be given to increasing the current recommended dietary allowance of 0-10 µg/d for adults in Scotland.


Assuntos
Dieta , Suplementos Nutricionais , Estilo de Vida , Deficiência de Vitamina D/epidemiologia , Vitamina D/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Escócia/epidemiologia , Espectrometria de Massas em Tandem
8.
Gut ; 59(12): 1670-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20844293

RESUMO

BACKGROUND: Previous studies have shown that aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) lower colorectal cancer (CRC) risk. However, the lowest effective NSAID dose, treatment duration, and effects on survival are not defined. In a large population-based case-control study, we have explored the relationship between NSAID dose and duration, CRC risk and overall CRC-specific survival. METHODS: The relationship between NSAID use and CRC risk was examined in 2279 cases and 2907 controls. Subjects completed food-frequency and lifestyle questionnaires. NSAID categories were low-dose aspirin (75 mg), non-aspirin NSAIDs (NA-NSAIDs) and any NSAID. Users were defined as taking >4 tablets/week for >1 month. ORs were calculated by logistic regression models and adjusted for potential confounding factors. Effect of NSAID use on all-cause and CRC-specific mortality was estimated using Logrank tests and Cox's hazard models. RESULTS: In all, 354 cases (15.5%) were taking low-dose aspirin compared to 526 controls (18.1%). Low-dose aspirin use was associated with decreased CRC risk (OR 0.78 95% CI 0.65 to 0.92, p=0.004), evident after 1 year and increasing with duration of use (p(trend)=0.004). NA-NSAID and any NSAID use were also inversely associated with CRC. There was no demonstrable effect of NSAIDS on all-cause (HR 1.11, p=0.22, 0.94-1.33) or CRC-specific survival (HR 1.01, p=0.93, 0.83-1.23). CONCLUSION: This is the first study to demonstrate a protective effect against CRC associated with the lowest dose of aspirin (75 mg per day) after only 5 years use in the general population. NSAID use prior to CRC diagnosis does not influence survival from the disease.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Anticarcinógenos/uso terapêutico , Aspirina/uso terapêutico , Neoplasias Colorretais/prevenção & controle , Adolescente , Adulto , Idoso , Anti-Inflamatórios não Esteroides/administração & dosagem , Anticarcinógenos/administração & dosagem , Aspirina/administração & dosagem , Neoplasias Colorretais/epidemiologia , Fatores de Confusão Epidemiológicos , Dieta/estatística & dados numéricos , Relação Dose-Resposta a Droga , Esquema de Medicação , Métodos Epidemiológicos , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Pobreza/estatística & dados numéricos , Escócia/epidemiologia , Fumar/epidemiologia , Adulto Jovem
9.
Front Genet ; 12: 621683, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305996

RESUMO

The current COVID-19 pandemic has unfortunately resulted in many significant concerns for individuals with genetic disorders and their relatives, regarding the viral infection and, particularly, its specific implications and additional advisable precautions for individuals affected by genetic disorders. To address this, the resulting requirement for guidance and information for the public and for genetics professionals was discussed among colleagues nationally, on the ScotGEN Steering Committee, and internationally on the Education Committee of the European Society of Human Genetics (ESHG). It was agreed that the creation of an online hub of genetics-related COVID-19 information resources would be particularly helpful. The proposed content, divided into a web page for professionals and a page for patients, was discussed with, and approved by, genetics professionals. The hub was created and provided online at www.scotgen.org.uk and linked from the ESHG's educational website for genetics and genomics, at www.eurogems.org. The new hub provides links, summary information and representative illustrations for a wide range of selected international resources. The resources for professionals include: COVID-19 research related hubs provided by Nature, Science, Frontiers, and PubMed; clinical guidelines; the European Centre for Disease Prevention and Control; the World Health Organisation; and molecular data sources including coronavirus 3D protein structures. The resources for patients and families include links to many accessible sources of support and relevant information. Since the launch of the pages, the website has received visits from over 50 countries worldwide. Several genetics consultants have commented on usefulness, clarity, readability, and ease of navigation. Visits have originated most frequently in the United Kingdom, Kuwait, Hong Kong, Moldova, United States, Philippines, France, and Qatar. More links have been added since the launch of the hub to include additional international public health and academic resources. In conclusion, an up-to-date online hub has been created and made freely available for healthcare professionals, patients, relatives and the public, providing categorised easily navigated links to a range of worldwide resources related to COVID-19. These pages are receiving a rapidly growing number of return visits and the authors continue to maintain and update the pages' content, incorporating new developments in this field of enormous worldwide importance.

10.
Hum Mutat ; 31(10): 1125-33, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20672378

RESUMO

Keratosis Follicularis Spinulosa Decalvans (KFSD) is a rare genetic disorder characterized by development of hyperkeratotic follicular papules on the scalp followed by progressive alopecia of the scalp, eyelashes, and eyebrows. Associated eye findings include photophobia in childhood and corneal dystrophy. Due to the genetic and clinical heterogeneity of similar disorders, a definitive diagnosis of KFSD is often challenging. Toward identification of the causative gene we reanalyzed a large Dutch KFSD family. SNP arrays (1 M) redefined the locus to a 2.9-Mb region at Xp22.12-Xp22.11. Screening of all 14 genes in the candidate region identified MBTPS2 as the candidate gene carrying a c.1523A>G (p.Asn508Ser) missense mutation. The variant was also identified in two unrelated X-linked KFSD families and cosegregated with KFSD in all families. In symptomatic female carriers, skewed X-inactivation of the normal allele matched with increased severity of symptoms. MBTPS2 is required for cleavage of sterol regulatory element-binding proteins (SREBPs). In vitro functional expression studies of the c.1523A>G mutation showed that sterol responsiveness was reduced by half. Other missense mutations in MBTPS2 have recently been identified in patients with IFAP syndrome. We postulate that both phenotypes are in the spectrum of one genetic disorder with a partially overlapping phenotype.


Assuntos
Doença de Darier/genética , Metaloendopeptidases/genética , Mutação de Sentido Incorreto , Cromossomos Humanos X/genética , Doença de Darier/diagnóstico , Doença de Darier/patologia , Feminino , Humanos , Masculino , Países Baixos , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Polimorfismo de Nucleotídeo Único
11.
Carcinogenesis ; 31(2): 296-301, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19945968

RESUMO

Mutations in the mitochondrial DNA (mtDNA) have been found to be present in several types of tumours including tumours of the large bowel. However, their role in cancer development and prognosis is still to be resolved. We used 2838 cases from a large Scottish colorectal cancer (CRC) case-control study to examine whether inherited genetic variation at the mtDNA influenced all-cause and CRC-specific mortality. We examined 140 tagging mtDNA variants including nine haplotypes commonly found in European populations. After applying three Cox proportional hazard models adjusted for American Joint Committee on Cancer (AJCC) stage, age and sex, three single nucleotide polymorphisms, two located in the 12S ribosomal RNA region (G752A and G1440A) and one in the nicotinamide adenine dinucleotide dehydrogenase subunit 2 region (ND2) region (G4770A), were statistically significantly associated with all-cause (Model I P-values: 0.0001, 0.002 and 0.002, respectively) and CRC-specific mortality (Model I P-values: 5 x 10(-5), 0.0003 and 0.0006, respectively). The H and U haplogroups were associated with an increased and decreased CRC risk, respectively, but with P-values of borderline significance and only after AJCC stage adjustment. In conclusion, the findings of the current study suggest a link between three common mtDNA variants and CRC prognosis. These findings are interesting and consistent with other biological knowledge but need to be confirmed through replication in independent cohorts.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , DNA Mitocondrial/genética , Polimorfismo de Nucleotídeo Único/genética , Adenocarcinoma/patologia , Idoso , Estudos de Casos e Controles , Neoplasias Colorretais/patologia , Feminino , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida
12.
Cancer Epidemiol Biomarkers Prev ; 29(2): 368-378, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792088

RESUMO

BACKGROUND: Tobacco smoking and alcohol consumption have been intensively studied in the general population to assess their effects on the risk of breast cancer, but very few studies have examined these effects in BRCA1 and BRCA2 mutation carriers. Given the high breast cancer risk for mutation carriers and the importance of BRCA1 and BRCA2 in DNA repair, better evidence on the associations of these lifestyle factors with breast cancer risk is essential. METHODS: Using a large international pooled cohort of BRCA1 and BRCA2 mutation carriers, we conducted retrospective (5,707 BRCA1 mutation carriers and 3,525 BRCA2 mutation carriers) and prospective (2,276 BRCA1 mutation carriers and 1,610 BRCA2 mutation carriers) analyses of alcohol and tobacco consumption using Cox proportional hazards models. RESULTS: For both BRCA1 and BRCA2 mutation carriers, none of the smoking-related variables was associated with breast cancer risk, except smoking for more than 5 years before a first full-term pregnancy (FFTP) when compared with parous women who never smoked. For BRCA1 mutation carriers, the HR from retrospective analysis (HRR) was 1.19 [95% confidence interval (CI), 1.02-1.39] and the HR from prospective analysis (HRP) was 1.36 (95% CI, 0.99-1.87). For BRCA2 mutation carriers, smoking for more than 5 years before an FFTP showed an association of a similar magnitude, but the confidence limits were wider (HRR = 1.25; 95% CI, 1.01-1.55 and HRP = 1.30; 95% CI, 0.83-2.01). For both carrier groups, alcohol consumption was not associated with breast cancer risk. CONCLUSIONS: The finding that smoking during the prereproductive years increases breast cancer risk for mutation carriers warrants further investigation. IMPACT: This is the largest prospective study of BRCA mutation carriers to assess these important risk factors.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Neoplasias da Mama/epidemiologia , Fumar Cigarros/epidemiologia , Estilo de Vida , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Neoplasias da Mama/prevenção & controle , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Pessoa de Meia-Idade , Mutação , Estudos Prospectivos , História Reprodutiva , Estudos Retrospectivos , Fatores de Risco
13.
N Engl J Med ; 354(26): 2751-63, 2006 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-16807412

RESUMO

BACKGROUND: The identification of mutations in germ-line DNA mismatch-repair genes at the time of diagnosis of colorectal cancer is important in the management of the disease. METHODS: Without preselection and regardless of family history, we recruited 870 patients under the age of 55 years soon after they received a diagnosis of colorectal cancer. We studied these patients for germ-line mutations in the DNA mismatch-repair genes MLH1, MSH2, and MSH6 and developed a two-stage model by multivariate logistic regression for the prediction of the presence of mutations in these genes. Stage 1 of the model incorporated only clinical variables; stage 2 comprised analysis of the tumor by immunohistochemical staining and tests for microsatellite instability. The model was validated in an independent population of patients. We analyzed 2938 patient-years of follow-up to determine whether genotype influenced survival. RESULTS: There were 38 mutations among the 870 participants (4 percent): 15 mutations in MLH1, 16 in MSH2, and 7 in MSH6. Carrier frequencies in men (6 percent) and women (3 percent) differed significantly (P<0.04). The addition of immunohistochemical analysis in stage 2 of the model had a sensitivity of 62 percent and a positive predictive value of 80 percent. There were 35 mutations in the validation series of 155 patients (23 percent): 19 mutations in MLH1, 13 in MSH2, and 3 in MSH6. The performance of the model was robust among a wide range of cutoff probabilities and was superior to that of the Bethesda and Amsterdam criteria for hereditary nonpolyposis colorectal cancer. Survival among carriers was not significantly different from that among noncarriers. CONCLUSIONS: We devised and validated a method of identifying patients with colorectal cancer who are carriers of mutations in DNA repair genes. Survival was similar among carriers and noncarriers.


Assuntos
Pareamento Incorreto de Bases/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo do DNA/genética , Mutação em Linhagem Germinativa , Heterozigoto , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Análise de Variância , Proteínas de Transporte/genética , Neoplasias Colorretais Hereditárias sem Polipose/mortalidade , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Feminino , Genótipo , Humanos , Imuno-Histoquímica , Modelos Logísticos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Prognóstico , Estudos Prospectivos , Análise de Sobrevida
14.
Hum Mutat ; 29(3): 367-74, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18033691

RESUMO

Identification of germline mutations in DNA mismatch repair genes in colorectal cancer probands without an extensive family history can be problematic when ascribing relevance to cancer causation. We undertook a structured assessment of the disease-causing potential of sequence variants identified in a prospective, population-based study of 932 colorectal cancer patients, diagnosed at <55 years of age. Patient samples were screened for germline mutations in MLH1, MSH2, and MSH6. Of 110 carriers, 74 (67%) had one of 33 rare variants of uncertain pathogenicity (12 MLH1, 11 MSH2, and 10 MSH6). Pathogenicity was assessed by determining segregation in families, allele frequency in large numbers of unaffected controls, effect on mRNA for putative splice-site mutations, effect on protein function by bioinformatic analysis and tumor microsatellite instability (MSI) status and DNA mismatch repair protein expression by immunohistochemistry. Because of the ambiguous nature of these variants and lack of concordance between functional assays and control allele frequency, we devised a scoring system to rank the degree of support for a pathogenic role. MLH1 c.200G>A p.G67E, MLH1 c.2041G>A p.A681T, and MSH2 c.2634+5G>C were categorized as pathogenic through assimilation of all available data, while 14 variants were categorized as benign (seven MLH1, three MSH2, and four MSH6). Interestingly, there is tentative evidence suggesting a possible protective effect of three variants (MLH1 c.2066A>G pQ689R, c.2146G>A p.V716M, and MSH2 c.965G>A p.G322D). These findings support a causal link with colorectal cancer for several DNA mismatch repair gene variants. However, the majority of missense changes are likely to be inconsequential polymorphisms.


Assuntos
Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA , Reparo do DNA/genética , Mutação em Linhagem Germinativa , Proteínas Adaptadoras de Transdução de Sinal/genética , Alelos , Sequência de Bases , Estudos de Casos e Controles , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/genética , Feminino , Frequência do Gene , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Estudos Prospectivos , Escócia
15.
Carcinogenesis ; 29(9): 1774-80, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18375958

RESUMO

In a large Scottish case-control study, we investigated the effects of adenomatous polyposis coli (APC) Asp1822Val (rs459552) and APC Glu1317Gln substitutions on colorectal cancer (CRC) risk and whether these associations were influenced by lifestyle and dietary factors. We did not observe any associations between the variants and CRC risk in the whole population. Post-menopausal women taking hormone replacement therapy (HRT) and participants who consumed a diet low in total fat, saturated fatty acids, monounsaturated fatty acids (MUFAs) and trans fatty acids had a lower risk of CRC [odds ratio (95% confidence interval): 0.53 (0.41, 0.68); 0.84 (0.72, 0.98); 0.72 (0.62, 0.85); 0.85 (0.73, 1.00) and 0.78 (0.67, 0.92), respectively]. This risk reduction was stronger in those homozygous for the variant APC 1822 allele with significant interaction relationships for HRT, red meat and MUFA intakes (P for interaction case-only design: 0.02, 0.002 and 0.02, respectively). Low n3 polyunsaturated fatty acids intake was associated with an increased CRC risk for the wild-type and heterozygous APC 1822 individuals but with a decreased CRC risk in those homozygous for the variant allele (P for interaction case-only design: 0.09). The interaction relationships with the APC 1317 variant were of the same direction though not significant, possibly due to the low frequency of the variant allele. Our results confirm the findings of three recent case-control studies suggesting a number of possible biological mechanisms. However, further large-scale studies are necessary in order to replicate these findings and confirm the role of these APC gene variants and their interaction with dietary and lifestyle exposures in colorectal carcinogenesis.


Assuntos
Neoplasias Colorretais/genética , Gorduras na Dieta/efeitos adversos , Genes APC/fisiologia , Variação Genética , Alelos , Substituição de Aminoácidos , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Feminino , Predisposição Genética para Doença , Homozigoto , Terapia de Reposição Hormonal , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Escócia/epidemiologia
16.
Int J Cancer ; 123(9): 2170-9, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18709640

RESUMO

Vitamin D has anticarcinogenic properties and might influence colorectal cancer (CRC) risk, but the epidemiological evidence is inconsistent. Many mechanisms of action for vitamin D have been proposed, with some of them initiating via its binding to the vitamin D receptor (VDR). Using a large Scottish case-control study, we investigated (i) main associations between CRC, vitamin D and calcium dietary intake and 4 VDR single nucleotide polymorphisms (rs10735810, rs1544410, rs11568820, rs7975232) and (ii) interaction associations between the VDR variants, vitamin D and calcium intakes. Inverse and dose-dependent associations were found between CRC risk, dietary [Odds ratio (OR) = 0.77, 95% confidence intervals (CI) 0.63, 0.92, p-trend = 0.012] and total vitamin D (OR = 0.80, 95% CI 0.65, 0.98, p-trend = 0.014) intake in multivariable-adjusted logistic regression models, whereas neither calcium intake nor any of the VDR variants were associated with CRC. Additionally, we observed statistically significant interactions (case-control, case-only designs) between vitamin D and calcium intake and rs10735810 (p-interaction 0.02, 0.006, respectively). We conducted meta-analyses of cohort, case-control and serum studies that also showed an inverse association between dietary vitamin D intake and CRC (serum studies: combined OR = 0.70, 95% CI 0.56, 0.87). The evidence of interaction we report here further supports the inverse association between vitamin D mediated through binding to the VDR.


Assuntos
Neoplasias Colorretais/prevenção & controle , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Vitamina D/administração & dosagem , Adolescente , Adulto , Idoso , Cálcio da Dieta/administração & dosagem , Estudos de Casos e Controles , Neoplasias Colorretais/etiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Receptores de Calcitriol/metabolismo , Risco , Vitamina D/metabolismo
17.
Cancer Epidemiol Biomarkers Prev ; 17(1): 171-82, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18199722

RESUMO

Vitamin B6, a coenzyme in the folate metabolism pathway, may have anticarcinogenic effects. Laboratory and epidemiologic studies support the hypothesis of its protective effect against colorectal cancer (CRC). The aim of this large Scottish case-control study, including 2,028 hospital-based cases and 2,722 population-based controls, was to investigate the associations between dietary and supplementary intake of vitamin B6 and CRC. Three logistic regression models adjusted for several confounding factors, including energy, folate, and fiber intake, were applied in the whole sample and after age, sex, cancer site, folate, MTHFR C677T (rs1801133), MTHFR A1298C (rs1801131), MTR A2756G (rs1805087), and MTRR A66G (rs1801394) stratification (analysis on genotypes on 1,001 cases and 1,010 controls < or =55 years old). Moderately strong inverse and dose-dependent associations in the whole sample were found between CRC risk and the intake of dietary and total vitamin B6 in all three models [model III: odds ratio (OR), 0.77; 95% confidence interval (95% CI), 0.61-0.98; P for trend = 0.03; OR, 0.86; 95% CI, 0.69-1.07; P for trend = 0.12]. In addition, meta-analyses of published studies showed inverse associations between vitamin B6 and CRC (combined relative risk, 0.81; 95% CI, 0.68-0.96; test for overall effect P = 0.01; combined odds ratio, 0.67; 95% CI, 0.60-0.75; test for overall effect P < 0.00001). Analysis within the stratified subgroups showed similar associations apart from a stronger effect among < or =55-year-old individuals. Evidence from larger cohort and experimental studies is now required to confirm and define the anticarcinogenic actions of vitamin B6 and to explore the mechanisms by which this effect is mediated.


Assuntos
Neoplasias Colorretais/epidemiologia , Dieta , Vitamina B 6/administração & dosagem , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Genótipo , Humanos , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Polimorfismo Genético , Estudos Prospectivos , Fatores de Risco , Escócia/epidemiologia
18.
JNCI Cancer Spectr ; 2(2): pky023, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31360853

RESUMO

BACKGROUND: For BRCA1 and BRCA2 mutation carriers, the association between oral contraceptive preparation (OCP) use and breast cancer (BC) risk is still unclear. METHODS: Breast camcer risk associations were estimated from OCP data on 6030 BRCA1 and 3809 BRCA2 mutation carriers using age-dependent Cox regression, stratified by study and birth cohort. Prospective, left-truncated retrospective and full-cohort retrospective analyses were performed. RESULTS: For BRCA1 mutation carriers, OCP use was not associated with BC risk in prospective analyses (hazard ratio [HR] = 1.08, 95% confidence interval [CI] = 0.75 to 1.56), but in the left-truncated and full-cohort retrospective analyses, risks were increased by 26% (95% CI = 6% to 51%) and 39% (95% CI = 23% to 58%), respectively. For BRCA2 mutation carriers, OCP use was associated with BC risk in prospective analyses (HR = 1.75, 95% CI = 1.03 to 2.97), but retrospective analyses were inconsistent (left-truncated: HR = 1.06, 95% CI = 0.85 to 1.33; full cohort: HR = 1.52, 95% CI = 1.28 to 1.81). There was evidence of increasing risk with duration of use, especially before the first full-term pregnancy (BRCA1: both retrospective analyses, P < .001 and P = .001, respectively; BRCA2: full retrospective analysis, P = .002). CONCLUSIONS: Prospective analyses did not show that past use of OCP is associated with an increased BC risk for BRCA1 mutation carriers in young middle-aged women (40-50 years). For BRCA2 mutation carriers, a causal association is also not likely at those ages. Findings between retrospective and prospective analyses were inconsistent and could be due to survival bias or a true association for younger women who were underrepresented in the prospective cohort. Given the uncertain safety of long-term OCP use for BRCA1/2 mutation carriers, indications other than contraception should be avoided and nonhormonal contraceptive methods should be discussed.

19.
Cancer Epidemiol Biomarkers Prev ; 16(7): 1416-21, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17627006

RESUMO

The AURKA oncogene is associated with abnormal chromosome segregation and aneuploidy and predisposition to cancer. Amplification of AURKA has been detected at higher frequency in tumors from BRCA1 and BRCA2 mutation carriers than in sporadic breast tumors, suggesting that overexpression of AURKA and inactivation of BRCA1 and BRCA2 cooperate during tumor development and progression. The F31I polymorphism in AURKA has been associated with breast cancer risk in the homozygous state in prior studies. We evaluated whether the AURKA F31I polymorphism modifies breast cancer risk in BRCA1 and BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2. Consortium of Investigators of Modifiers of BRCA1/2 was established to provide sufficient statistical power through increased numbers of mutation carriers to identify polymorphisms that act as modifiers of cancer risk and can refine breast cancer risk estimates in BRCA1 and BRCA2 mutation carriers. A total of 4,935 BRCA1 and 2,241 BRCA2 mutation carriers and 11 individuals carrying both BRCA1 and BRCA2 mutations was genotyped for F31I. Overall, homozygosity for the 31I allele was not significantly associated with breast cancer risk in BRCA1 and BRCA2 carriers combined [hazard ratio (HR), 0.91; 95% confidence interval (95% CI), 0.77-1.06]. Similarly, no significant association was seen in BRCA1 (HR, 0.90; 95% CI, 0.75-1.08) or BRCA2 carriers (HR, 0.93; 95% CI, 0.67-1.29) or when assessing the modifying effects of either bilateral prophylactic oophorectomy or menopausal status of BRCA1 and BRCA2 carriers. In summary, the F31I polymorphism in AURKA is not associated with a modified risk of breast cancer in BRCA1 and BRCA2 carriers.


Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas Serina-Treonina Quinases/genética , Adulto , Idade de Início , Aurora Quinase A , Aurora Quinases , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Taxa de Sobrevida
20.
J Clin Oncol ; 23(24): 5588-96, 2005 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-16110018

RESUMO

PURPOSE: To assess the effectiveness of annual ovarian cancer screening (transvaginal ultrasound and serum CA-125 estimation) in detecting presymptomatic ovarian cancer in women at increased genetic risk. PATIENTS AND METHODS: A cohort of 1,110 women at increased risk of ovarian cancer were screened between January 1991 and March 2004; 553 were moderate-risk individuals (4% to 10% lifetime risk) and 557 were high-risk individuals (> 10% lifetime risk). Outcome measurements include the number and stage of screen-detected cancers, the number and stage of cancers not detected at screening, the number of equivocal screening results requiring recall/repetition, and the number of women undergoing surgery for benign disease. RESULTS: Thirteen epithelial ovarian malignancies (12 invasive and one borderline), developed in the cohort. Ten tumors were detected at screening: three International Federation of Gynecology and Obstetrics (FIGO) stage I (including borderline), two stage II, four stage III, and one stage IV. Of the three cancers not detected by screening, two were stage III and one was stage IV; 29 women underwent diagnostic surgery but were found not to have ovarian cancer. CONCLUSION: Annual surveillance by transvaginal ultrasound scanning and serum CA-125 measurement in women at increased familial risk of ovarian cancer is ineffective in detecting tumors at a sufficiently early stage to influence prognosis. With a positive predictive value of 17% and a sensitivity of less than 50%, the performance of ultrasound does not satisfy the WHO screening standards. In addition, the combined protocol has a particularly high false-positive rate in premenopausal women, leading to unnecessary surgical intervention.


Assuntos
Antígeno Ca-125/sangue , Programas de Rastreamento/normas , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/diagnóstico por imagem , Adulto , Feminino , Predisposição Genética para Doença , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/genética , Medição de Risco , Ultrassonografia
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