RESUMO
BACKGROUND: Triple-negative (TN) tumours are the predominant breast cancer subtype in BRCA1 mutation carriers. Recently, it was proposed that all individuals below 50 years of age with TN breast cancer should be offered BRCA testing. We have evaluated the BRCA1 mutation frequency and the implications for clinical practice of undertaking genetic testing in women with TN breast cancer. METHODS: We undertook BRCA1 mutation analysis in 308 individuals with TN breast cancer, 159 individuals from unselected series of breast cancer and 149 individuals from series ascertained on the basis of young age and/or family history. RESULTS: BRCA1 mutations were present in 45 out of 308 individuals. Individuals with TN cancer <50 years had >10% likelihood of carrying a BRCA1 mutation in both the unselected (11 out of 58, 19%) and selected (26 out of 111, 23%) series. However, over a third would not have been offered testing using existing criteria. We estimate that testing all individuals with TN breast cancer <50 years would generate an extra 1200 tests annually in England. CONCLUSION: Women with TN breast cancer diagnosed below 50 years have >10% likelihood of carrying a BRCA1 mutation and are therefore eligible for testing in most centres. However, implementation may place short-term logistical and financial burdens on genetic services.
Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Testes Genéticos , Fatores Etários , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/metabolismo , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Humanos , Incidência , Pessoa de Meia-Idade , Mutação , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismoRESUMO
OBJECTIVE: To examine trends in mechanism and outcome of major traumatic injury in adults since the implementation of the New South Wales trauma monitoring program, and to identify factors associated with mortality. DESIGN AND SETTING: Retrospective review of NSW Trauma Registry data from 1 January 2003 to 31 December 2007, including patient demographics, year of injury, and level of trauma centre where definitive treatment was provided. PARTICIPANTS: 9769 people aged ≥ 15 years hospitalised for trauma, with an injury severity score (ISS) > 15. MAIN OUTCOME MEASURES: The NSW Trauma Registry outcome measures included were overall hospital length of stay, length of stay in an intensive care unit and in ospital mortality. RESULTS: There was a decreasing trend in severe trauma presentations in the age group 16-34 years, and an increasing trend in presentations of older people, particularly those aged ≥ 75 years. Road trauma and falls were consistently the commonest injury mechanisms. There were 1328 inhospital deaths (13.6%). Year of injury, level of trauma centre, ISS, head/neck injury and age were all independent predictors of mortality. The odds of mortality was significantly higher among patients receiving definitive care at regional trauma centres compared with Level I centres (odds ratio, 1.34; 95% CI, 1.10-1.63). CONCLUSIONS: Deaths from major trauma in NSW trauma centres have declined since 2003, and definitive care at a Level 1 trauma centre was associated with a survival benefit. More comprehensive trauma data collection with timely analysis will improve injury surveillance and better inform health policy in NSW.
Assuntos
Ferimentos e Lesões/mortalidade , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Mortalidade Hospitalar , Humanos , Escala de Gravidade do Ferimento , Tempo de Internação/estatística & dados numéricos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , New South Wales/epidemiologia , Razão de Chances , Transferência de Pacientes/estatística & dados numéricos , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Centros de Traumatologia/normas , Centros de Traumatologia/estatística & dados numéricos , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/etiologia , Ferimentos e Lesões/terapia , Adulto JovemRESUMO
Heterozygous fumarate hydratase (FH) germline mutations cause hereditary leiomyomatosis and renal cell cancer (HLRCC), an autosomal dominant syndrome characterized by multiple cutaneous piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer. The main objective of our study was to evaluate clinical and genetic data from families suspected of HLRCC on a nationwide level. All families referred for FH mutation analysis in the Netherlands were assessed. We performed FH sequence analysis and multiplex ligation-dependent probe amplification. Families with similar FH mutations were examined for haplotype sharing. In 14 out of 33 families, we identified 11 different pathogenic FH germline mutations, including 4 novel mutations and 1 whole-gene deletion. Clinical data were available for 35 FH mutation carriers. Cutaneous leiomyomas were present in all FH mutation carriers older than 40 years of age. Eleven out of 21 female FH mutation carriers underwent surgical treatment for symptomatic uterine leiomyomas at an average of 35 years. Two FH mutation carriers had papillary type 2 renal cancer and Wilms' tumour, respectively. We evaluated the relevance of our findings for clinical practice and have proposed clinical diagnostic criteria, indications for FH mutation analysis and recommendations for management.
Assuntos
Carcinoma de Células Renais/genética , Fumarato Hidratase , Mutação em Linhagem Germinativa , Neoplasias Renais/genética , Leiomiomatose , Neoplasias Cutâneas/genética , Neoplasias Uterinas/genética , Adolescente , Adulto , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/enzimologia , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Fumarato Hidratase/genética , Predisposição Genética para Doença , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/enzimologia , Leiomiomatose/enzimologia , Leiomiomatose/genética , Países Baixos , Linhagem , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/enzimologia , Síndrome , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/enzimologia , Adulto JovemRESUMO
BACKGROUND: A novel oncogenetic clinic was established in 2002 at the Royal Marsden NHS Foundation Trust offering advice and specialist follow-up for families with a germline mutation in BRCA1 or BRCA2. The remit of this multidisciplinary clinic, staffed by individuals in both oncology and genetics, is to provide individualised screening recommendations, support in decision making, risk reducing strategies, cascade testing, and an extensive research portfolio. METHODS: A retrospective analysis was performed to evaluate uptake of genetic testing, risk reducing surgery and cancer prevalence in 346 BRCA1/BRCA2 families seen between January 1996 and December 2006. RESULTS: 661 individuals attended the clinic and 406 mutation carriers were identified; 85.8% mutation carriers have chosen to attend for annual follow-up. 70% of mutation carriers elected for risk reducing bilateral salpingo-oophorectomy (RRBSO). 32% of unaffected women chose risk reducing bilateral mastectomy. 32% of women with breast cancer chose contralateral risk reducing mastectomy at time of diagnosis. Some women took over 8 years to decide to have surgery. 91% of individuals approached agreed to participate in research programmes. INTERPRETATION: A novel specialist clinic for BRCA1/2 mutation carriers has been successfully established. The number of mutation positive families is increasing. This, and the high demand for RRBSO in women over 40, is inevitably going to place an increasing demand on existing health resources. Our clinic model has subsequently been adopted in other centres and this will greatly facilitate translational studies and provide a healthcare structure for management and follow-up of such people who are at a high cancer risk.
Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/prevenção & controle , Neoplasias Ovarianas/prevenção & controle , Adulto , Idoso , Proteínas Reguladoras de Apoptose , Neoplasias da Mama/cirurgia , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/cirurgia , Medicina Preventiva , Estudos Retrospectivos , Comportamento de Redução do RiscoRESUMO
Germline mutations in the mismatch repair (MMR) genes are associated with Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC) syndrome. Here, we characterise a variant of hMLH1 that confers a loss-of-function MMR phenotype. The mutation changes the highly conserved Gly67 residue to a glutamate (G67E) and is reminiscent of the hMLH1-p.Gly67Arg mutation, which is present in several Lynch syndrome cohorts. hMLH1-Gly67Arg has previously been shown to confer loss-of-function (Shimodaira et al, 1998), and two functional assays suggest that the hMLH1-Gly67Glu protein fails to sustain normal MMR functions. In the first assay, hMLH1-Gly67Glu abolishes the protein's ability to interfere with MMR in yeast. In the second assay, mutation of the analogous residue in yMLH1 (yMLH1-Gly64Glu) causes a loss-of-function mutator phenotype similar to yMLH1-Gly64Arg. Despite these molecular similarities, an unusual spectrum of tumours is associated with hMLH1-Gly67Glu, which is not typical of those associated with Lynch syndrome and differs from those found in families carrying the hMLH1-Gly67Arg allele. This suggests that hMLH1 may have different functions in certain tissues and/or that additional factors may modify the influence of hMLH1 mutations in causing Lynch syndrome.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/genética , Mutação/genética , Proteínas Nucleares/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias Colorretais Hereditárias sem Polipose/metabolismo , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Família , Teste de Complementação Genética , Humanos , Immunoblotting , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteínas Nucleares/metabolismo , Fenótipo , SaccharomycetalesRESUMO
OBJECTIVES: Genetic testing for the breast and ovarian cancer susceptibility genes BRCA1 and BRCA2 has important implications for the clinical management of people found to carry a mutation. However, genetic testing is expensive and may be associated with adverse psychosocial effects. To provide a cost-efficient and clinically appropriate genetic counselling service, genetic testing should be targeted at those individuals most likely to carry pathogenic mutations. Several algorithms that predict the likelihood of carrying a BRCA1 or a BRCA2 mutation are currently used in clinical practice to identify such individuals. DESIGN: We evaluated the performance of the carrier prediction algorithms BOADICEA, BRCAPRO, IBIS, the Manchester scoring system and Myriad tables, using 1934 families seen in cancer genetics clinics in the UK in whom an index patient had been screened for BRCA1 and/or BRCA2 mutations. The models were evaluated for calibration, discrimination and accuracy of the predictions. RESULTS: Of the five algorithms, only BOADICEA predicted the overall observed number of mutations detected accurately (ie, was well calibrated). BOADICEA also provided the best discrimination, being significantly better (p<0.05) than all models except BRCAPRO (area under the receiver operating characteristic curve statistics: BOADICEA = 0.77, BRCAPRO = 0.76, IBIS = 0.74, Manchester = 0.75, Myriad = 0.72). All models underpredicted the number of BRCA1 and BRCA2 mutations in the low estimated risk category. CONCLUSIONS: Carrier prediction algorithms provide a rational basis for counselling individuals likely to carry BRCA1 or BRCA2 mutations. Their widespread use would improve equity of access and the cost-effectiveness of genetic testing.
Assuntos
Genes BRCA1 , Genes BRCA2 , Testes Genéticos/métodos , Modelos Estatísticos , Algoritmos , Neoplasias da Mama/genética , Feminino , Aconselhamento Genético , Predisposição Genética para Doença , Humanos , Neoplasias Ovarianas/genética , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e EspecificidadeRESUMO
We report a patient with Bloom syndrome, a rare autosomal recessive condition characterised by chromosomal instability leading to a high risk of cancer at an early age. The diagnosis should be considered in patients with any cancer of significantly early onset, short stature and a photosensitive lupus-like rash on the face. Diagnostic confirmation is obtained from chromosome studies that show significantly increased numbers of sister chromatid exchanges. There are important management implications, including minimising the use of ionising radiation in surveillance and treatment.
Assuntos
Síndrome de Bloom/complicações , Neoplasias/diagnóstico , Neoplasias/terapia , Adulto , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/terapia , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/terapia , Feminino , Humanos , Programas de Rastreamento , Neoplasias/etiologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/terapiaRESUMO
We have conducted a telelink telephone-led cancer genetic counselling model at The Royal Marsden NHS Foundation Trust. The study commenced in March 2004 and evaluation of the clinic was conducted over 17 months from March 2005 to the end of July 2006. A total of 612 patients had telephone consultations during this time, 228 of whom were referred from primary care with a median of 30 patients counselled per month (range of 19-63, depending on staff availability with average of two staff per clinic). Waiting times were measured for General Practitioner referrals and all 228 were counselled within the national target-stipulated 13 weeks (median 6 weeks, range 1-12). An additional 132 patients who were sent appointment letters after receipt of their family history questionnaires did not attend their appointments (18% of all potential referrals) and required recontacting by letter. After telephone counselling, 42% of patients were able to be discharged from the telephone clinic without a subsequent face-to-face appointment, thereby saving resources. The telephone clinic also had a short set-up time with flexibility on timing and day of administration, which would be an advantage in centres where outreach clinic facilities are scarce. The telelink telephone counselling model is highly efficient in triaging high risk individuals for face-to-face counselling as per the Kenilworth model, in effecting concentration of resources and in providing a flexible individual-centred approach to cancer genetic counselling delivery.
Assuntos
Aconselhamento Genético/métodos , Neoplasias/genética , Telefone , Adulto , Atenção à Saúde , Feminino , Aconselhamento Genético/organização & administração , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Encaminhamento e Consulta , Reino UnidoRESUMO
One hundred eighteen cases of nevoid basal cell carcinoma syndrome (NBCCS, Gorlin's syndrome or basal cell nevus syndrome) are presented in this study. In aiming to ascertain all the affected families in Australia, we have examined the largest series to date. Relative frequencies of associated complications are presented and compared with those of the recent English survey by Evans et al. [J Med Genet 30:460-464, 1993]. The frequencies of most manifestations are similar. However, one major difference is that the multiple basal cell carcinomas are manifest from an earlier age in the Australian population, which probably reflects greater exposure to ultraviolet radiation. Of the 64 families ascertained, 37 represented simplex cases, and, accordingly, the apparent new mutation rate is surprisingly high (14-81%) given the lack of impact of NBCCS on reproductive capabilities. There is some evidence to suggest that this may be attributable to anticipation.
Assuntos
Síndrome do Nevo Basocelular , Anormalidades Múltiplas/genética , Adolescente , Adulto , Idade de Início , Alelos , Austrália/epidemiologia , Síndrome do Nevo Basocelular/diagnóstico , Síndrome do Nevo Basocelular/epidemiologia , Síndrome do Nevo Basocelular/genética , Osso e Ossos/anormalidades , Calcinose/genética , Criança , Pré-Escolar , Mapeamento Cromossômico , Cromossomos Humanos Par 9 , Dura-Máter/patologia , Feminino , Ligação Genética , Testes Genéticos , Humanos , Lactente , Doenças Maxilomandibulares/genética , Ceratodermia Palmar e Plantar/genética , Masculino , Pessoa de Meia-Idade , Mutação , Nova Zelândia/epidemiologia , Cistos Odontogênicos/genética , Palato/anormalidades , Fenótipo , Prevalência , País de Gales/epidemiologiaRESUMO
The demonstration that mutations in the Patched (PTCH) gene cause nevoid basal cell carcinoma syndrome (NBCCS) has led to the identification of the exact molecular lesion in a percentage of individuals with the syndrome. In addition, it has been possible to determine, through molecular analysis of parents and other relatives of these individuals, if the mutation is inherited or has arisen de novo. We have previously reported 28 mutations in individuals with NBCCS, and here we present an additional 4 novel mutations. We have also analyzed relatives of a number of the individuals in whom we have found mutations. In total we have identified 8 individuals who carry a de novo mutation in the PTCH gene. In 5 of these cases, clinical and radiological examination had not unequivocally ruled out a diagnosis in one of the parents. This helps to define the clinical phenotype and suggests that diagnostic criteria in this complex syndrome may require review.
Assuntos
Síndrome do Nevo Basocelular/genética , Proteínas de Membrana/genética , Mutação , Análise Mutacional de DNA , DNA de Neoplasias/análise , Éxons , Humanos , Repetições de Microssatélites , Receptores Patched , Receptor Patched-1 , Fenótipo , Polimorfismo Conformacional de Fita Simples , Receptores de Superfície CelularRESUMO
A comparison of paraprotein estimation by immunoturbidimetry (IT) and electrophoresis followed by scanning densitometry (EFD) showed significant differences in concentration for IgG, IgA, and IgM paraproteins. Overestimation of IgM paraproteins by IT was particularly marked. Our data suggest that both techniques should be used for IgG and IgA paraproteins but for IgM paraproteins IT was found to be unsuitable and EFD is the method of choice.
Assuntos
Paraproteínas/análise , Eletroforese das Proteínas Sanguíneas , Densitometria , Eletroforese em Gel de Poliacrilamida , Humanos , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Mieloma Múltiplo/sangue , Nefelometria e Turbidimetria , Paraproteinemias/sangue , Macroglobulinemia de Waldenstrom/sangueRESUMO
The major clinical stigmata of basal cell naevus syndrome (BCNS) appear in adolescence and adult life but some occult skeletal abnormalities are congenital. BCNS is dominantly inherited and it would be useful to identify, as early in life as possible, which of the offspring of patients with BCNS are at risk of developing the syndrome. Radiographs of the neck and chest of 80 patients with BCNS diagnosed confidently on clinical criteria have been examined for abnormalities which were considered to be congenital skeletal anomalies. Congenital abnormalities of the cervical and thoracic spine, mainly spina bifida occulta, were found in 45%. Congenital abnormalities of ribs were found in 49% and of the shoulder(s) in 36%. Overall congenital abnormalities were shown on the neck or chest radiograph in 55 (69%) patients. The presence of one or more of these congenital abnormalities on the chest or neck radiograph of a child who is the offspring of a person with BCNS makes it extremely likely that the child also has BCNS. The absence of these features, and of any clinical features of BCNS, would suggest that the risk of the child developing BCNS has been reduced from the prior expectation of 50% to approximately half that (24%).
Assuntos
Síndrome do Nevo Basocelular/complicações , Vértebras Cervicais/anormalidades , Vértebras Torácicas/anormalidades , Adulto , Síndrome do Nevo Basocelular/diagnóstico por imagem , Vértebras Cervicais/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Costelas/anormalidades , Costelas/diagnóstico por imagem , Ombro/anormalidades , Ombro/diagnóstico por imagem , Espinha Bífida Oculta/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagemRESUMO
The purpose of our study was to identify the incidence of falcine calcification shown on plain skull radiographs in people with basal cell naevus syndrome (BCNS) and in their relatives compared with a normal population. A population of people with BCNS and their relatives was identified on non-radiological grounds and the incidence of falcine calcification on skull radiographs in each of these two groups was compared with the incidence of falcine calcification in a control group of people and of a larger group who attended casualty departments. Falcine calcification was graded into dense, fine but definite, and faint. 85 people with BCNS had nearly 100% incidence of falcine calcification in adults. 83 first degree unaffected relatives showed no excess over "normal" incidence of falcine calcification. In the 970 casualty patients some falcine calcification was common (> 20%) in males over 30 and in females over 50 years of age. It occurred earlier and was more common in males than in females. Dense calcification occurred in 5-7% of females and males over 60 years of age. Dense calcification was rare (< 2%) under the age of 40 years. In conclusion, falcine calcification should be regarded as the fourth major feature and a very important diagnostic feature of BCNS. An adult labelled as a BCNS sufferer without falcine calcification probably has not got the syndrome. The genetic defect responsible for the metabolic defect resulting in dural calcification is probably the same as, or in close linkage disequilibrium to, that responsible for the major clinical features of the syndrome. The age and sex distribution of falcine calcification in a general hospital casualty population is described.
Assuntos
Síndrome do Nevo Basocelular/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Neoplasias Cranianas/diagnóstico por imagem , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Calcinose/complicações , Criança , Pré-Escolar , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Fatores SexuaisRESUMO
OBJECTIVES: Pedestrian and pedal cycle injuries are important causes of child morbidity and mortality. The combination of Bayesian methods and geographical distribution maps may assist public health practitioners to identify communities at high risk of injury. METHODS: Data were obtained on all hospitalizations of children from NSW (Australia), for pedestrian and pedal cycle injuries, from 2000-2001 to 2004-2005. Using Bayesian methods, posterior expected rate ratios (as an estimate of smoothed standardized hospitalization ratios for each injury mechanism) were mapped by local government area (LGA) across the state. RESULTS: There were over 7,000 hospitalizations for pedestrian and pedal cycle injuries. High risk LGAs accounted for more than one third of hospitalized pedestrian and pedal cycle injuries in NSW. CONCLUSIONS: LGAs at high risk for pedestrian injury tended to be urbanized metropolitan areas with a high population density, while high risk LGAs for pedal cycle injury tended to be either in urban regional areas, or on the margin of urbanized metropolitan areas. Geospatial analyses can assist policymakers and practitioners to identify high risk communities for which public health interventions can be prioritized.
Assuntos
Ciclismo/lesões , Prioridades em Saúde , Saúde Pública , Caminhada/lesões , Ferimentos e Lesões/epidemiologia , Adolescente , Teorema de Bayes , Criança , Pré-Escolar , Feminino , Hospitalização/tendências , Humanos , Lactente , Governo Local , Masculino , New South Wales/epidemiologiaRESUMO
Immunohistochemistry of tumour samples is increasingly used in the triage of families where hereditary non-polyposis colorectal cancer (HNPCC) due to mismatch repair defects is suspected. Usually, this is undertaken in tumours that are a recognised part of the spectrum of HNPCC-related cancers e.g. colon or endometrial cancers. Although breast cancers are not classed as part of this spectrum, this study examined the extent to which some breast tumours do arise by the mismatch repair pathway in these families. This may have clinical utility in families where an individual with a 'classic HNPPC-related' tumour is not available for evaluation. Immunohistochemistry of a breast tumour may identify an individual in whom germline mutation testing is worthwhile.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais/genética , Mutação em Linhagem Germinativa , Neoplasias Colorretais/imunologia , Neoplasias Colorretais Hereditárias sem Polipose/classificação , Neoplasias Colorretais Hereditárias sem Polipose/imunologia , Análise Mutacional de DNA , Feminino , Testes Genéticos , Humanos , Imuno-Histoquímica , Masculino , LinhagemRESUMO
Burns are a significant cause of morbidity and mortality in children. Although industrialized countries have achieved significant declines in deaths and hospitalizations for these injuries in recent decades, the benefits have not been shared equally by children across all socioeconomic groups. We used Bayesian methods to map posterior expected relative risks, as an estimate of smoothed hospital separation ratios for fire and burns in children, across local government areas in New South Wales, Australia. The geographic pattern of relative risk varied by age group; higher than average risks were observed for children residing in rural and remote areas, as well as in scattered local government areas closer to the coast and in some metropolitan regions. Mapping the occurrence of injury gives injury practitioners the opportunity to identify high risk communities for further investigation of risk factors and implementation of targeted interventions within a defined area.
Assuntos
Queimaduras/epidemiologia , Incêndios/estatística & dados numéricos , Acidentes/estatística & dados numéricos , Adolescente , Distribuição por Idade , Teorema de Bayes , Criança , Pré-Escolar , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Masculino , New South Wales/epidemiologia , Fatores de Risco , Fatores Socioeconômicos , Saúde da População UrbanaRESUMO
Deleterious mutations in the BRCA1 gene predispose women to an increased risk of breast and ovarian cancer. Many functional studies have suggested that BRCA1 has a role in DNA damage repair and failure in the DNA damage response pathway often leads to the accumulation of chromosomal aberrations. Here, we have compared normal lymphocytes with those heterozygous for a BRCA1 mutation. Short-term cultures were irradiated (8Gy) using a high dose rate and subsequently metaphases were analysed by 24-colour chromosome painting (M-FISH). We scored the chromosomal rearrangements in the metaphases from five BRCA1 mutation carriers and from five noncarrier control samples 6 days after irradiation. A significantly higher level of chromosomal damage was detected in the lymphocytes heterozygous for BRCA1 mutations compared with normal controls; the average number of aberrations per mitosis was 3.48 compared with 1.62 in controls (P=0.0001). This provides new evidence that heterozygous mutation carriers have a different response to DNA damage compared with noncarriers and that BRCA1 has a role in DNA damage surveillance. Our finding has implications for treatment and screening of BRCA1 mutation carriers using modalities that involve irradiation.
Assuntos
Dano ao DNA/efeitos da radiação , Genes BRCA1 , Heterozigoto , Linfócitos/efeitos da radiação , Aberrações Cromossômicas , Feminino , Humanos , MutaçãoRESUMO
We wished to establish the frequency, regularity and laterality of multiple ovulation in mothers of dizygotic (DZ) twins and controls. Subjects had regular menses and were not using oral contraceptives. Ovarian ultrasound scans were taken over a number of cycles in 21 mothers of DZ twins and 18 controls (including 13 mothers of monozygotic [MZ] twins). Multiple large follicles (greater than or equal to 12 mm diameter) were seen significantly more frequently in mothers of DZ twins (13/21 mothers, 24/77 cycles, average +/- SE follicles/cycle 1.34 +/- 0.11) than controls (2/18 mothers, 3/31 cycles, average 1.10 +/- 0.08). Both ipsilateral and contralateral multiple follicles were observed. In one case a mother of DZ twins showed multiple large follicles in 7 out of 10 cycles in which she was scanned, including both ipsi- and contralateral patterns of occurrence.
Assuntos
Gravidez Múltipla/fisiologia , Superovulação/fisiologia , Gêmeos Dizigóticos , Adulto , Feminino , Fase Folicular/genética , Fase Folicular/fisiologia , Humanos , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/crescimento & desenvolvimento , Gravidez , Gravidez Múltipla/genética , Superovulação/genética , Gêmeos Dizigóticos/genética , UltrassonografiaRESUMO
The GSTM1 gene on chromosome 1p encodes the carcinogen-detoxification enzyme, glutathione S-transferase (mu subclass). The homozygous null genotype at this locus has been associated with increased susceptibility to malignancy, including some skin cancers. One hundred and twenty-four Australian patients with sporadic melanoma and 62 with familial basal cell carcinomas (a feature of nevoid basal cell carcinoma syndrome, NBCCS) were examined for germline homozygous deletions of GSTM1 using multiplex polymerase chain reactions. The homozygous null genotype was not overrepresented in either those with a single melanoma or in the NBCCS cases. Nor did it significantly accelerate tumorigenesis in either group. Analyses of much larger sample sizes will be required to investigate the representation of the null genotype in patients with multiple melanoma primaries and in those with melanoma co-existing with other non-cutaneous malignancies.
Assuntos
Carcinoma Basocelular/genética , Glutationa Transferase/genética , Melanoma/genética , Neoplasias Cutâneas/genética , Carcinoma Basocelular/enzimologia , Genótipo , Humanos , Melanoma/enzimologia , Neoplasias Cutâneas/enzimologiaRESUMO
Basal cell carcinomas (BCCs) are the most common sporadic cancers worldwide. They are also a cardinal manifestation of a familial cancer predisposition syndrome, naevoid BCC syndrome (NBCCS). The gene responsible for NBCCS is likely to be a tumour suppressor gene and has been genetically mapped to a 2cM region between microsatellite markers, D9S196 and D9S180 at 9q22.3-q31. 101 BCCs (63 sporadic and 38 familial) were examined for loss of heterozygosity (LOH) in the candidate region of the NBCCS gene. Deletions were found in 46% and all LOH is consistent with genetic mapping of the NBCC locus. These findings strongly support the hypothesis that inactivation of the putative tumour suppressor, the NBCCS gene, is important in the formation of sporadic BCCs. One sporadic tumour indicates that the smallest region of overlap of these deletions is within the interval between D9S287 and D9S180. If this is confirmed in additional tumours, it would further narrow down the NBCCS region and exclude one candidate gene, that for the C complementation group of Fanconi anaemia, which maps proximally to D9S287. However, it would not exclude another candidate, the gene for the A complementation group of xeroderma pigmentosum (XPAC). Evidence of imprinting was also sought but preliminary data indicate that it is unlikely to occur at the NBCCS locus.