RESUMEN
Despite the routine nature of comparing sequence variations identified during clinical testing to database records, few databases meet quality requirements for clinical diagnostics. To address this issue, The Royal College of Pathologists of Australasia (RCPA) in collaboration with the Human Genetics Society of Australasia (HGSA), and the Human Variome Project (HVP) is developing standards for DNA sequence variation databases intended for use in the Australian clinical environment. The outputs of this project will be promoted to other health systems and accreditation bodies by the Human Variome Project to support the development of similar frameworks in other jurisdictions.
RESUMEN
OBJECTIVE: The purpose of this study was the clinical and pathological characterisation of a new autosomal dominant gastric polyposis syndrome, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). METHODS: Case series were examined, documenting GAPPS in three families from Australia, the USA and Canada. The affected families were identified through referral to centralised clinical genetics centres. RESULTS: The report identifies the clinical and pathological features of this syndrome, including the predominant dysplastic fundic gland polyp histology, the exclusive involvement of the gastric body and fundus, the apparent inverse association with current Helicobacter pylori infection and the autosomal dominant mode of inheritance. CONCLUSIONS: GAPPS is a unique gastric polyposis syndrome with a significant risk of gastric adenocarcinoma. It is characterised by the autosomal dominant transmission of fundic gland polyposis, including areas of dysplasia or intestinal-type gastric adenocarcinoma, restricted to the proximal stomach, and with no evidence of colorectal or duodenal polyposis or other heritable gastrointestinal cancer syndromes.
Asunto(s)
Adenocarcinoma/diagnóstico , Síndromes Neoplásicos Hereditarios/diagnóstico , Pólipos/diagnóstico , Neoplasias Gástricas/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/microbiología , Adenocarcinoma/patología , Adolescente , Adulto , Anciano , Niño , Femenino , Genes Dominantes , Infecciones por Helicobacter/complicaciones , Helicobacter pylori/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Síndromes Neoplásicos Hereditarios/genética , Síndromes Neoplásicos Hereditarios/microbiología , Síndromes Neoplásicos Hereditarios/patología , Linaje , Pólipos/genética , Pólipos/patología , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patologíaRESUMEN
OBJECTIVE: To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported. PATIENTS AND METHODS: Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation. RESULTS: In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant. CONCLUSIONS: The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.
Asunto(s)
Detección Precoz del Cáncer/métodos , Genes BRCA1 , Genes BRCA2 , Predisposición Genética a la Enfermedad/genética , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/diagnóstico , Adulto , Anciano , Detección Precoz del Cáncer/normas , Métodos Epidemiológicos , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Mutación , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/genéticaRESUMEN
There is accumulating evidence that women with breast cancer due to a familial BRCA1 or BRCA2 mutation benefit from specific surgical and chemotherapeutic treatment strategies. However, the rapid identification of such patients during the acute phase of treatment raises a number of issues. This study investigated Australian opinion leaders' views on the issues arising from such 'treatment-focused' genetic testing. Semi-structured interviews with 34 opinion leaders working in cancer genetics were undertaken. Interviewees acknowledged the introduction of treatment-focused DNA testing has the potential to positively transform the management of breast cancer patients, but were concerned that certain ethical and logistical issues have yet to be addressed. These include decision-making and consent, the familial nature of genetic information, and the management of genetics services within familial cancer clinics in the public hospital system in Australia. Service providers will need to have policies and strategies for managing the increased demand. It will also be necessary to include genetic counseling services within familial cancer clinics in the care pathway for newly diagnosed patients prior to any DNA testing to determine adjuvant treatment; such services may be more cost-effective than expecting surgeons and medical oncologists to fulfill this role.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/terapia , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , Pruebas Genéticas/métodos , Pautas de la Práctica en Medicina , Australia , Neoplasias de la Mama/genética , Toma de Decisiones , Familia , Femenino , Pruebas Genéticas/organización & administración , Humanos , Consentimiento Informado , Pautas de la Práctica en Medicina/organización & administraciónRESUMEN
PURPOSE: Despite the established importance of the role of family history in prostate cancer, relatively little research encompasses the psychosocial issues relevant to unaffected men with a family history of prostate cancer. To determine the completeness and quality of available literature on the issues faced by men with a high risk of prostate cancer, we conducted a multidisciplinary review of the literature to provide some guidance on the information that clinicians might provide to men who are concerned about family history. MATERIALS AND METHODS: A structured literature search was conducted by a multidisciplinary team of clinicians and researchers who reviewed the medical and psychosocial literature, and identified 21 relevant studies. RESULTS: Research suggests that many high risk patients are concerned about the risk of prostate cancer, and some may significantly overestimate that risk. Several studies have shown high screening rates among high risk patients and high levels of interest in genetic testing for prostate cancer risk should it become available, yet many men also report a desire for more information about their personal risk and risk management options. CONCLUSIONS: Given the lack of clear data on the efficacy of prostate cancer screening among high risk patients, clinicians could consider providing men who are concerned about family history with information on their personal risk, help them to clarify the potential benefits, limitations and harms of prostate cancer screening in their situation, and then support their choice regarding the management of prostate cancer risk.
Asunto(s)
Salud de la Familia , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/genéticaRESUMEN
BACKGROUND: Mutations in the MUTYH gene, which codes for a base excision repair protein, have recently been found to cause an autosomal recessive syndrome characterized by multiple colorectal adenomas and increased risk of colorectal cancer. To identify key areas for clinical research, it is necessary to understand the current management of MUTYH-associated neoplasia. METHODS: Twelve questionnaires were sent to experts from familial colorectal cancer services throughout Australia, including representatives from all Australian states. The questionnaire was designed to clarify the practical management of MUTYH-associated neoplasia in the patient and their family. RESULTS: All 12 questionnaires were returned. For patients with fewer than 100 colorectal adenomas, and no dominant family history of colorectal neoplasia, most respondents carried out MUTYH testing before or concomitantly with APC. Australian laboratories generally carried out an initial directed analysis of the MUTYH gene for the two common mutations Y165C and G382D. For patients with biallelic MUTYH mutations all respondents endorsed regular colonoscopy surveillance with an interval of 1-2 years, whereas the recommended surveillance for monoallelic mutation carriers varied. CONCLUSION: This is the first study to document current management practices for MUTYH-associated neoplasia and forms a basis for the development of evidence-based recommendations as further research becomes available. Current guidelines for testing and management of MUTYH-associated neoplasia are discussed.
Asunto(s)
Neoplasias Colorrectales/genética , Neoplasias Colorrectales/terapia , ADN Glicosilasas/genética , Adenoma/diagnóstico , Adenoma/genética , Adenoma/terapia , Sustitución de Aminoácidos/genética , Australia , Neoplasias Colorrectales/diagnóstico , Manejo de la Enfermedad , Humanos , Guías de Práctica Clínica como Asunto/normas , Factores de Riesgo , Encuestas y Cuestionarios/normas , SíndromeRESUMEN
A genetic counselor is often faced with the difficult task of conveying a set of complex and highly abstract factors associated with the client's risk of developing a familial disorder. The client is faced with the even more difficult task of making significant health-related decisions about an event which may or may not eventuate. Although there is a large corpus of research on this topic, much of the knowledge on risk communication is difficult to apply in a practical context. In this paper we draw together some insights on risk communication and decision-making under conditions of uncertainty, and apply them directly to the problem of communicating familial cancer risk. In particular, we focus on the distinction between individual risk and observed frequencies of adverse events, various framing effects, and contextualizing risk communication. We draw attention to some of the potential pitfalls in counseling about risk and offer avenues for circumventing them.
Asunto(s)
Comunicación , Asesoramiento Genético/métodos , Marcadores Genéticos/genética , Predisposición Genética a la Enfermedad/psicología , Neoplasias/genética , Relaciones Profesional-Paciente , Proteína BRCA1/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/prevención & control , Neoplasias de la Mama/psicología , Femenino , Tamización de Portadores Genéticos , Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas/psicología , Humanos , Funciones de Verosimilitud , Neoplasias/prevención & control , Neoplasias/psicología , Neoplasias Ováricas/genética , Neoplasias Ováricas/prevención & control , Neoplasias Ováricas/psicología , Probabilidad , Pronóstico , RiesgoRESUMEN
OBJECTIVE: To increase the awareness among at risk relatives of the availability of genetic testing for a familial disorder while respecting their autonomy and privacy. METHODS: This was a comparison of preintervention and postintervention cohorts of families carried out in a state wide clinical service providing genetic counselling and testing for people at risk of familial adult onset cancer. Unaffected relatives who were not clients of the service in 74 kindreds with familial mutations causing familial breast and ovarian cancer, hereditary non-polyposis colorectal cancer, or Cowden syndrome were included in the study. In the baseline cohort (41 kindreds), family members who were clients of the clinical service and had been shown to be carriers of mutations were asked to advise relatives that genetic testing was available. In the intervention cohort (33 kindreds), the clinical service obtained consent to advise at risk relatives by letter that genetic testing was available. The main outcome measures were: (a) proportion of unaffected first and second degree relatives of the proband in each family whose genetic status was clarified within 2 years of the mutation being identified in the family, and (b) concerns regarding privacy and autonomy voiced by relatives receiving these letters. RESULTS: In the baseline cohort, the average proportion of relatives in each family whose genetic status was clarified was 23%. In the intervention cohort, the average proportion of relatives in each family whose genetic status was clarified was 40% (p = 0.001). None of the relatives in the intervention cohort complained of a breach of privacy or autonomy. CONCLUSION: Clinical services can take an effective and proactive approach to notifying relatives who are not their clients of the availability of genetic testing without compromising principles of privacy and autonomy.
Asunto(s)
Ética Clínica , Salud de la Familia , Enfermedades Genéticas Congénitas/diagnóstico , Enfermedades Genéticas Congénitas/genética , Pruebas Genéticas/ética , Adolescente , Estudios de Cohortes , Correspondencia como Asunto , HumanosRESUMEN
Cowden syndrome (OMIM No 158350) is a pleomorphic, autosomal dominant syndrome characterised by hamartomas in tissues derived from the endoderm, mesoderm, and ectoderm. It is caused by germline mutations in the PTEN gene and is allelic to the Bannayan-Riley-Ruvalcaba and Lhermitte-Duclos syndromes. The three syndromes are defined on clinical grounds but there is overlap in their definitions. The clinical features include trichilemmomas, verrucose lesions of the skin, macrocephaly, intellectual disability, cerebellar gangliocytoma, thyroid adenomas, fibroadenomas of the breast, and hamartomatous colonic polyps. Cutaneous haemangiomas are occasionally noted. Malignancies often arise in the affected tissues. Visceral arteriovenous malformations are a recognised component of the Bannayan-Riley-Ruvalcaba syndrome but have been reported rarely in Cowden syndrome. A family is described with a clinical diagnosis of Cowden syndrome, a familial frameshift mutation in the PTEN gene, and large visceral arteriovenous malformations. The association of these pleomorphic syndromes with arteriovenous malformations can be explained by the putative role of the PTEN gene in suppressing angiogenesis. Recognition of arteriovenous malformations as a clinical feature of Cowden syndrome has implications for the clinical management of patients with this disorder.
Asunto(s)
Malformaciones Arteriovenosas/diagnóstico , Síndrome de Hamartoma Múltiple/diagnóstico , Adulto , Malformaciones Arteriovenosas/diagnóstico por imagen , Malformaciones Arteriovenosas/genética , Análisis Mutacional de ADN , Femenino , Mutación del Sistema de Lectura , Síndrome de Hamartoma Múltiple/genética , Humanos , Persona de Mediana Edad , Fosfohidrolasa PTEN/genética , RadiografíaRESUMEN
A recent report based on 68 families, including 17 with mutations in BRCA1, suggested that there was an excess of female offspring born to BRCA1 mutation carriers. We have examined the gender ratio among offspring of 511 mutation carriers from 116 BRCA1 families, 77 and 39 from Australia and the United States, respectively. We found no evidence for a significant deviation from the expected proportion of female offspring in the Australian pedigrees, but there was an excess of female offspring in pedigrees from the USA. Ascertainment bias probably explains this bias, rather than a link with X-chromosome inactivation as previously suggested, because the families from the USA were ascertained for the purposes of linkage studies whereas those from Australia were ascertained through Familial Cancer Clinics to which they had been referred for clinical genetic counseling and mutation testing.
Asunto(s)
Genes BRCA1 , Genes BRCA2 , Heterocigoto , Razón de Masculinidad , Adulto , Australia/epidemiología , Neoplasias de la Mama/genética , Cromosomas Humanos X , Estudios de Cohortes , Femenino , Humanos , Recién Nacido , Masculino , Neoplasias Ováricas/genética , Linaje , Estados Unidos/epidemiologíaAsunto(s)
Predisposición Genética a la Enfermedad , Pruebas Genéticas/ética , Pruebas Genéticas/organización & administración , Neoplasias/genética , Femenino , Asesoramiento Genético , Humanos , Incidencia , Masculino , Neoplasias/epidemiología , Neoplasias/patología , Evaluación de Programas y Proyectos de Salud , Medición de Riesgo , Sensibilidad y Especificidad , Australia del Sur/epidemiologíaRESUMEN
This longitudinal study aimed to document (i) the information-giving and patient-communication styles of clinical geneticists and genetic counsellors (consultants) in familial breast cancer clinics and (ii) assess the effect of these styles on women's knowledge, whether their expectations were met, satisfaction, risk perception and psychological status. A total of 158 women from high-risk breast cancer families completed self-report questionnaires at 2 weeks preconsultation and 4 weeks postconsultation. The consultations were audiotaped, transcribed and coded. Multivariate logistic regressions showed that discussing prophylactic mastectomy (P=0.00) and oophorectomy (P=0.01) led to women having significantly more expectations met; discussing genetic testing significantly decreased anxiety (P=0.03) and facilitating understanding significantly decreased depression (P=0.05). Receiving a summary letter of the consultation significantly lowered anxiety (P=0.01) and significantly increased the accuracy of perceived risk (P=0.02). Women whose consultant used more supportive communications experienced significantly more anxiety about breast cancer at the 4 weeks follow-up (P=0.00). These women were not significantly more anxious before genetic counselling. In conclusion, this study found that consultants vary in the amount of information they give and the way they communicate; and this variation can result in better or worse psychosocial outcomes. Greater use of supportive and counselling communications appeared to increase anxiety about breast cancer. Identifying methods to assist consultants to address emotional issues effectively may be helpful.
Asunto(s)
Ansiedad , Neoplasias de la Mama/genética , Comunicación , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Relaciones Profesional-Paciente , Derivación y Consulta , Adulto , Anciano , Neoplasias de la Mama/prevención & control , Neoplasias de la Mama/psicología , Instituciones Oncológicas , Femenino , Humanos , Conocimiento , Estudios Longitudinales , Mastectomía , Salud Mental , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Satisfacción del Paciente , Pronóstico , Factores de RiesgoRESUMEN
A patient with microcephaly, microphthalmia, ectrodactyly, and prognathism (MMEP) and mental retardation was previously reported to carry a de novo reciprocal t(6;13)(q21;q12) translocation. In an attempt to identify the presumed causative gene, we mapped the translocation breakpoints using fluorescence in situ hybridisation (FISH). Two overlapping genomic clones crossed the breakpoint on the der(6) chromosome, locating the breakpoint region between D6S1594 and D6S1250. Southern blot analysis allowed us to determine that the sorting nexin 3 gene (SNX3) was disrupted. Using Inverse PCR, we were able to amplify and sequence the der(6) breakpoint region, which exhibited homology to a BAC clone that contained marker D13S250. This clone allowed us to amplify and sequence the der(13) breakpoint region and to determine that no additional rearrangement was present at either breakpoint, nor was another gene disrupted on chromosome 13. Therefore, the translocation was balanced and SNX3 is probably the candidate gene for MMEP in the patient. However, mutation screening by dHPLC and Southern blot analysis of another sporadic case with MMEP failed to detect any point mutations or deletions in the SNX3 coding sequence. Considering the possibility of positional effect, another candidate gene in the vicinity of the der(6) chromosome breakpoint may be responsible for MMEP in the original patient or, just as likely, the MMEP phenotype in the two patients results from genetic heterogeneity.
Asunto(s)
Anomalías Múltiples/genética , Proteínas Portadoras/genética , Cromosomas Humanos Par 13/genética , Cromosomas Humanos Par 6/genética , Microcefalia/genética , Prognatismo/genética , Translocación Genética/genética , Proteínas de Transporte Vesicular/genética , Empalme Alternativo/genética , Secuencia de Aminoácidos , Secuencia de Bases , Proteínas Portadoras/química , Rotura Cromosómica/genética , Clonación Molecular , Análisis Mutacional de ADN , Femenino , Deformidades Congénitas del Pie/genética , Heterogeneidad Genética , Humanos , Hibridación Fluorescente in Situ , Discapacidad Intelectual/genética , Masculino , Datos de Secuencia Molecular , Fenotipo , Mapeo Físico de Cromosoma , Sitios de Empalme de ARN/genética , Nexinas de Clasificación , Proteínas de Transporte Vesicular/químicaRESUMEN
This multicentre study examined the influence of patient demographic, disease status and psychological variables on clinical geneticists/genetic counsellors (consultants) behaviours in initial consultations with women from high-risk breast cancer families. One hundred and fifty-eight women completed a pre-clinic self-report questionnaire. The consultations were audiotaped, transcribed verbatim and coded. Consultants did not vary their behaviour according to women's expectations. However, significantly more aspects of genetic testing were discussed with women who were affected with breast cancer (P<0.001), screening and management with unaffected women (P=0.01) and breast cancer prevention with younger women (P=0.01). Prophylactic mastectomy was discussed more frequently with women with medical and allied health training (P=0.02), and prophylactic oophorectomy with women affected with breast cancer (P=0.03), those in non-professional occupations (P=0.04) and with a family history of breast and ovarian cancer (P<0.001). Consultants used significantly more behaviours to facilitate understanding with women who were in non-professional occupations (P=0.04); facilitated active patient involvement more with women affected with breast cancer (P<0.001) and used more supportive and counselling behaviours with affected women (P=0.02). This study showed that patient demographics were more likely to predict consultants' communication behaviours than the woman's psychological status. Methods to facilitate assessment of psychological morbidity are needed to allow more tailored communication.
Asunto(s)
Neoplasias de la Mama/psicología , Comunicación , Asesoramiento Genético , Educación en Salud , Síndromes Neoplásicos Hereditarios/psicología , Grabación en Cinta , Mujeres/psicología , Adulto , Australia/epidemiología , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/prevención & control , Análisis Mutacional de ADN , Emociones , Asesoramiento Genético/métodos , Asesoramiento Genético/psicología , Pruebas Genéticas/psicología , Humanos , Conocimiento , Mastectomía/psicología , Síndromes Neoplásicos Hereditarios/epidemiología , Síndromes Neoplásicos Hereditarios/genética , Ocupaciones , Ovariectomía , Aceptación de la Atención de Salud , Educación del Paciente como Asunto , Participación del Paciente , Riesgo , Muestreo , Encuestas y CuestionariosRESUMEN
RAD51 colocalizes with both BRCA1 and BRCA2, and genetic variants in RAD51 would be candidate BRCA1/2 modifiers. We searched for RAD51 polymorphisms by sequencing 20 individuals. We compared the polymorphism allele frequencies between female BRCA1/2 mutation carriers with and without breast or ovarian cancer and between population-based ovarian cancer cases with BRCA1/2 mutations to cases and controls without mutations. We discovered two single nucleotide polymorphisms (SNPs) at positions 135 g-->c and 172 g-->t of the 5' untranslated region. In an initial group of BRCA1/2 mutation carriers, 14 (21%) of 67 breast cancer cases carried a "c" allele at RAD51:135 g-->c, whereas 8 (7%) of 119 women without breast cancer carried this allele. In a second set of 466 mutation carriers from three centers, the association of RAD51:135 g-->c with breast cancer risk was not confirmed. Analyses restricted to the 216 BRCA2 mutation carriers, however, showed a statistically significant association of the 135 "c" allele with the risk of breast cancer (adjusted odds ratio, 3.2; 95% confidence limit, 1.4-40). BRCA1/2 mutation carriers with ovarian cancer were only about one half as likely to carry the RAD51:135 g-->c SNP. Analysis of the RAD51:135 g-->c SNP in 738 subjects from an Israeli ovarian cancer case-control study was consistent with a lower risk of ovarian cancer among BRCA1/2 mutation carriers with the "c" allele. We have identified a RAD51 5' untranslated region SNP that may be associated with an increased risk of breast cancer and a lower risk of ovarian cancer among BRCA2 mutation carriers. The biochemical basis of this risk modifier is currently unknown.
Asunto(s)
Neoplasias de la Mama/genética , Proteínas de Unión al ADN/genética , Predisposición Genética a la Enfermedad/genética , Neoplasias Ováricas/genética , Adulto , Anciano , Anciano de 80 o más Años , Australia , Proteína BRCA1/genética , Proteína BRCA2 , Estudios de Casos y Controles , Femenino , Humanos , Israel , Judíos/genética , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Polimorfismo Genético , Recombinasa Rad51 , Factores de Transcripción/genética , Estados UnidosRESUMEN
This multicenter study evaluated the impact of genetic counseling in 218 women at risk of developing hereditary breast cancer. Women were assessed prior to counseling and 12-month post-counseling using self-administered, mailed questionnaires. Compared to baseline, breast cancer genetics knowledge was increased significantly at follow-up, and greater increases in knowledge were associated with educational level. Breast cancer anxiety decreased significantly from baseline to follow-up, and these decreases were associated with improvements in perceived risk. A significant decrease in clinical breast examination was observed at the 12-month follow-up. Findings suggest that women with a family history of breast cancer benefit from attending familial cancer clinics as it leads to increases in breast cancer genetics knowledge and decreases in breast cancer anxiety. The lowered rates of clinical breast examination indicate that the content of genetic counseling may need to be reviewed to ensure that women receive and take away the right message.
Asunto(s)
Neoplasias de la Mama/genética , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Adaptación Psicológica , Adolescente , Adulto , Anciano , Australia , Neoplasias de la Mama/prevención & control , Neoplasias de la Mama/psicología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Modelos Logísticos , Persona de Mediana Edad , Estadísticas no ParamétricasRESUMEN
We describe two children with a brain defect similar to that described as 'microlissencephaly', as defined in Barkovich et aL [(1998) Neuroped 29: 113-119]. Concomitant malformations (cardiac, spinal, urogenital) may represent components of a wider syndrome complex; alternatively, or additionally, there may have been a valproate teratogenic effect. The inheritance is likely to be autosomal recessive, although X-linkage cannot be excluded.
Asunto(s)
Anomalías Múltiples/patología , Encéfalo/anomalías , Cardiopatías Congénitas/patología , Columna Vertebral/anomalías , Anomalías Urogenitales/patología , Anomalías Inducidas por Medicamentos , Anomalías Múltiples/genética , Anticonvulsivantes/efectos adversos , Enfermedades Fetales/patología , Cardiopatías Congénitas/genética , Humanos , Lactante , Masculino , Microcefalia/genética , Microcefalia/patología , Linaje , Fenotipo , Anomalías Urogenitales/genética , Ácido Valproico/efectos adversosRESUMEN
Opitz syndrome (OS) is a genetically heterogeneous malformation disorder. Patients with OS may present with a variable array of malformations that are indicative of a disturbance of the primary midline developmental field. Mutations in the C-terminal half of MID1, an RBCC (RING, B-box and coiled-coil) protein, have recently been shown to underlie the X-linked form of OS. Here we show that the MID1 gene spans at least 400 kb, almost twice the distance originally reported and has a minimum of six mRNA isoforms as a result of the alternative use of 5' untranslated exons. In addition, our detailed mutational analysis of MID1 in a cohort of 15 patients with OS has resulted in the identification of seven novel mutations, two of which disrupt the N-terminus of the protein. The most severe of these (E115X) is predicted to truncate the protein before the B-box motifs. In a separate patient, a missense change (L626P) was found that also represents the most C-terminal alteration reported to date. As noted with other C-terminal mutations, GFP fusion constructs demonstrated that the L626P mutant formed cytoplasmic clumps in contrast to the microtubular distribution seen with the wild-type sequence. Notably, however, both N-terminal mutants showed no evidence of cytoplasmic aggregation, inferring that this feature is not pathognomonic for X-linked OS. These new data and the finding of linkage to MID1 in the absence of a demonstrable open reading frame mutation in a further family support the conclusion that X-linked OS results from loss of function of MID1.
Asunto(s)
Anomalías Múltiples/genética , Ligamiento Genético , Proteínas de Microtúbulos , Mutación , Proteínas Nucleares , Factores de Transcripción/genética , Factores de Transcripción/fisiología , Secuencias de Aminoácidos , Núcleo Celular/metabolismo , Codón sin Sentido , Citoplasma/metabolismo , ADN Complementario , Exones , Femenino , Humanos , Masculino , Microtúbulos/metabolismo , Mutación Missense , Sistemas de Lectura Abierta , Linaje , Proteínas Recombinantes de Fusión/metabolismo , Síndrome , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas , Cromosoma X , Dedos de ZincAsunto(s)
Actitud , Neoplasias de la Mama/psicología , Predisposición Genética a la Enfermedad/psicología , Pruebas Genéticas/psicología , Adulto , Edad de Inicio , Ansiedad , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Femenino , Humanos , Consentimiento Informado , Persona de Mediana Edad , Encuestas y CuestionariosRESUMEN
PURPOSE: To assess intention to undergo prophylactic bilateral mastectomy and psychologic determinants in unaffected women at increased risk of developing hereditary breast cancer. PATIENTS AND METHODS: Three hundred thirty-three women who were awaiting their initial appointments for risk assessment, advice about surveillance, and prophylactic options at one of 14 familial cancer clinics participated in a cross-sectional, questionnaire-based survey. RESULTS: Nineteen percent of women would consider and 47% would not consider a prophylactic mastectomy, should genetic testing identify a mutation in a breast cancer-predisposing gene, whereas 34% were unsure and 1% had already undergone a prophylactic mastectomy. In a bivariate analysis, women at a moderately increased risk of developing breast cancer had the highest proportion of subjects reporting that they would consider a prophylactic mastectomy (25%), compared with women at high risk (16%) (chi(2) = 7.79; P =.051). In multivariate analyses, consideration of prophylactic mastectomy strongly correlated with high levels of breast cancer anxiety (odds ratio [OR] = 17.4; 95% confidence interval [CI], 4.35 to 69.71; P =. 0001) and overestimation of one's breast cancer risk (OR = 3.01; 95% CI, 1.43 to 6.32; P =.0036), whereas there was no association with objective breast cancer risk (P =.60). CONCLUSION: A significant proportion of women at increased risk of developing hereditary breast cancer would consider prophylactic mastectomy. Although prophylactic mastectomy may be appropriate in women at high risk of developing breast cancer, it is perhaps less so in those who have a moderately increased risk. Such moderate-risk women are likely to benefit from interventions aimed at reducing breast cancer anxiety and correcting exaggerated breast cancer risk perceptions.