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Our objective was to assess the reported history of seizures in cognitively asymptomatic mutation carriers for autosomal dominant Alzheimer's disease (ADAD) and the predictive value of seizures for mutation carrier status in cognitively asymptomatic first-degree relatives of ADAD patients. Seizure occurrence in the Dominantly Inherited Alzheimer Network observational study was correlated with mutation carrier status in cognitively asymptomatic subjects. Of 276 cognitively asymptomatic individuals, 11 (4%) had experienced seizures, and nine of these carried an ADAD mutation. Thus, in the Dominantly Inherited Alzheimer Network population, seizure frequency in mutation carriers was significantly higher than in noncarriers (p = 0.04), and the positive predictive value of seizures for the presence of a pathogenic mutation was 81.8%. Among cognitively asymptomatic ADAD family members, the occurrence of seizures increases the a priori risk of 50% mutation-positive status to about 80%. This finding suggests that ADAD mutations increase the risk of seizures.
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Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/genética , Genes Dominantes/genética , Estudios de Asociación Genética , Heterocigoto , Mutación/genética , Convulsiones/etiología , Convulsiones/genética , Adulto , Femenino , Humanos , Masculino , Estudios Observacionales como Asunto , Valor Predictivo de las Pruebas , RiesgoRESUMEN
In 1983, Huntington disease (HD) became the first disease to be mapped to a previously unknown location on chromosome 4. This discovery meant that we could now identify whether some individuals at risk for HD would develop HD in the future using a method called linkage testing. Testing was first offered through research protocols designed to assess whether testing could be done safely in this population. Testing guidelines were soon developed by the Huntington's Disease Society of America and the International Huntington Association in collaboration with the World Federation of Neurology. The gene for HD was found in 1993, allowing for direct gene testing for the mutant HTT allele. This chapter will discuss the development of guidelines and recent revisions to the guidelines, prenatal testing, and testing in three complicated situations: (1) the testing of minors; (2) anonymous testing; and (3) testing individuals at 25% risk. Studies examining the outcomes of predictive testing will also be discussed. Outcome studies have shown that testing can be done safely in the context of testing protocols that include neurologic examinations, pretest counseling, psychiatric/psychologic assessment, results in person, and available follow-up support. It appears that anxiety and depression prior to testing are better predictors of psychologic status after testing than the test result itself.
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Pruebas Genéticas/métodos , Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/genética , Depresión/psicología , Asesoramiento Genético , HumanosRESUMEN
The relationship between body-mass index (BMI) and Alzheimer´s disease (AD) has been extensively investigated. However, BMI alterations in preclinical individuals with autosomal dominant AD (ADAD) have not yet been investigated. We analyzed cross-sectional data from 230 asymptomatic members of families with ADAD participating in the Dominantly Inherited Alzheimer Network (DIAN) study including 120 preclinical mutation carriers (MCs) and 110 asymptomatic non-carriers (NCs). Differences in BMI and their relation with cerebral amyloid load and episodic memory as a function of estimated years to symptom onset (EYO) were analyzed. Preclinical MCs showed significantly lower BMIs compared to NCs, starting 11.2 years before expected symptom onset. However, the BMI curves begun to diverge already at 17.8 years before expected symptom onset. Lower BMI in preclinical MCs was significantly associated with less years before estimated symptom onset, higher global Aß brain burden, and with lower delayed total recall scores in the logical memory test. The study provides cross-sectional evidence that weight loss starts one to two decades before expected symptom onset of ADAD. Our findings point toward a link between the pathophysiology of ADAD and disturbance of weight control mechanisms. Longitudinal follow-up studies are warranted to investigate BMI changes over time.
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Enfermedad de Alzheimer/patología , Índice de Masa Corporal , Portador Sano , Pérdida de Peso , Estudios Transversales , Humanos , Estudios LongitudinalesRESUMEN
Tumor profiling (TP) is primarily used to identify driver mutations within a tumor for treatment purposes, but it may also identify germline mutations. Current involvement of cancer genetic counselors (GCs) in the TP process is not clear. Members of the National Society of Genetic Counselors Cancer Special Interest Group were invited to participate in a confidential, web-based survey to characterize current practices and attitudes related to the use of TP. Of 105 useable responses, 86.7% of GCs reported their institutions were using TP, although only 6.7% did this routinely. Although 63.7% reported personal involvement in the process, largely with result interpretation and follow-up germline testing, 69.7% reported seeing fewer than 5 patients for this reason and 97.9% desired further education on this topic. Work and regional setting were not predictors of involvement with TP; however, GCs in the academic setting were less aware of who obtains consent (p = 0.001). GCs reported they were not often utilized as a resource regarding TP. Overall, GCs believed TP is beneficial in identifying hereditary cancer syndromes, although most reported finding a germline mutation in <10% of cases. This study provides a snapshot of current GC involvement with TP, and documents the desire by GCs for additional education on tumor profiling.
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Actitud del Personal de Salud , Consejeros , Asesoramiento Genético , Hallazgos Incidentales , Síndromes Neoplásicos Hereditarios/diagnóstico , Síndromes Neoplásicos Hereditarios/genética , Adulto , Femenino , Humanos , MasculinoRESUMEN
Gerstmann-Sträussler-Scheinker Disease (GSS) is a familial neurodegenerative disorder characterized clinically by ataxia, parkinsonism, and dementia, and neuropathologically by deposition of diffuse and amyloid plaques composed of prion protein (PrP). The purpose of this study was to evaluate if [(11)C]Pittsburgh Compound B (PiB) positron emission tomography (PET) is capable of detecting PrP-amyloid in PRNP gene carriers. Six individuals at risk for GSS and eight controls underwent [(11)C]PiB PET scans using standard methods. Approximately one year after the initial scan, each of the three asymptomatic carriers (two with PRNP P102L mutation, one with PRNP F198S mutation) underwent a second [(11)C]PiB PET scan. Three P102L carriers, one F198S carrier, and one non-carrier of the F198S mutation were cognitively normal, while one F198S carrier was cognitively impaired during the course of this study. No [(11)C]PiB uptake was observed in any subject at baseline or at follow-up. Neuropathologic study of the symptomatic individual revealed PrP-immunopositive plaques and tau-immunopositive neurofibrillary tangles in cerebral cortex, subcortical nuclei, and brainstem. PrP deposits were also numerous in the cerebellar cortex. This is the first study to investigate the ability of [(11)C]PiB PET to bind to PrP-amyloid in GSS F198S subjects. This finding suggests that [(11)C]PiB PET is not suitable for in vivo assessment of PrP-amyloid plaques in patients with GSS.
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Relationships between industry and university-based researchers have been commonplace for decades and have received notable attention concerning the conflicts of interest these relationships may harbor. While new efforts are being made to update conflict of interest policies and make industry relationships with academia more transparent, the development of broader institutional partnerships between industry and academic health centers challenges the efficacy of current policy to effectively manage these innovative partnerships. In this paper, we argue that existing strategies to reduce conflicts of interest are not sufficient to address the emerging models of industry-academic partnerships because they focus too narrowly on financial matters and are not comprehensive enough to mitigate all ethical risk. Moreover, conflict-of-interest strategies are not designed to promote best practices nor the scientific and social benefits of academic-industry collaboration. We propose a framework of principles and benchmarks for "ethically credible partnerships" between industry and academic health centers and describe how this framework may provide a practical and comprehensive approach for designing and evaluating such partnerships.
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Predictive testing for Huntington disease (HD) has been available in the United States (US) since 1987, and the Indiana University Predictive Testing Program has been providing this testing since 1990. To date there has been no published description of those who present for such testing in the US. Here we describe demographics of 141 individuals and reproductive decision making of a subset of 16 of those individuals who underwent predictive HD testing between 1990 and 2010 at one site in the US. This study is a retrospective chart review of the "Personal History Questionnaire" participants completed prior to testing. As seen in other studies, most participants were female (64.5 %), in their mid-30s (mean = 34), and had at least one child prior to testing (54 %). Multiple demographic datum points are described, and the reproductive decision making of these at-risk individuals was analyzed using Fisher's Exact Tests. Of those women who had children before learning of their risk to inherit HD, those who attended church more frequently, had three or more children total, or whose mother was affected with HD were more likely to be comfortable with their choice to have children. We conclude that these demographic factors influence the reproductive decision-making of individuals at risk for HD. Psychologists, clinical geneticists, and genetic counselors may be able to use this information to help counsel at-risk patients regarding current or past reproductive decision making.
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Demografía , Enfermedad de Huntington/diagnóstico , Reproducción , Adolescente , Adulto , Anciano , Femenino , Humanos , Enfermedad de Huntington/genética , Enfermedad de Huntington/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Myotonic dystrophy type 1 is an autosomal dominant condition caused by a trinucleotide CTG repeat expansion in the 3' untranslated region of the dystrophia myotonica protein kinase gene. The phenotypic features of myopathic facies, generalized weakness, and myotonia are thought to be dependent on repeat number, with larger expansions generally leading to earlier and/or more severe disease. The vast majority of individuals are heterozygous for an expanded allele and an allele in the normal range. In this clinical report, we describe two brothers with congenital myotonic dystrophy type 1. The younger of the two siblings is one of only 13 homozygous patients ever reported in the literature. He carries two expanded alleles: one with 1,170 repeats and the other with >100 repeats. We present his clinical picture in relation to his more severely affected heterozygous brother as well as other published homozygous cases. Finally, we discuss the inconsistency between repeat size and symptomatic expression as it applies to the current proposed mechanisms of myotonic dystrophy type 1 pathogenicity.
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Discapacidades del Desarrollo/genética , Homocigoto , Distrofia Miotónica/genética , Expansión de Repetición de Trinucleótido , Regiones no Traducidas 3' , Alelos , Preescolar , Heterocigoto , Humanos , Hidrocefalia/genética , Hidrocefalia/terapia , Lactante , Distrofia Miotónica/etiología , Hermanos , TraqueostomíaRESUMEN
Frontotemporal dementia (FTD) is an umbrella term for a heterogeneous group of neurodegenerative disorders that are characterized by changes in cognition, language, personality, and social functioning. Approximately 40% of individuals with FTD have a family history of dementia, but less than 10% have a clear autosomal dominant pattern of inheritance. However, establishing a clear mode of inheritance in FTD is complicated by clinical heterogeneity, variable expression, phenocopies, misdiagnosis, early death due to other causes, missing medical records, and lost family histories. Mutations in the microtubule-associated protein tau and progranulin genes have been reported in the majority of hereditary cases, making genetic testing of at-risk individuals possible. The first step in counseling a family with a history of FTD is to take a comprehensive family history with confirmation of any diagnosis in a family member with medical records to the extent possible. If the pedigree analysis suggests an autosomal dominant pattern of inheritance, genetic testing of an affected relative may be offered to the family to determine if a mutation is present. If a mutation is found, relatives interested in pursuing genetic testing should be referred to a genetic counselor familiar with genetic testing for neurodegenerative disorders. Predictive testing of unaffected and at-risk relatives should only be offered in the context of a comprehensive genetic counseling protocol offering pre- and post-test counseling and support. One survey of at-risk individuals in a large family with FTD found that 50% were interested in testing. In one study actually offering genetic testing for FTD, the rate of uptake of testing was only 8.4%. A more recent study estimated the uptake for testing for FTD to be somewhere between 7% and 17% and attributed the low uptake to family resistance to testing. While genetic testing may be appropriate for some families with Alzheimer's disease and FTD, uptake of testing may be expected to be low.
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Demencia Frontotemporal/genética , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Adenosina Trifosfatasas/genética , Proteínas de Ciclo Celular/genética , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Demencia Frontotemporal/diagnóstico , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Mutación , Progranulinas , Factores de Riesgo , Proteína que Contiene Valosina , Proteínas tau/genéticaRESUMEN
Most of the research on reproduction in those at risk for Huntington Disease (HD) has focused on the impact of genetic testing on reproductive decision-making. The main goal has been to determine whether discovering one is a carrier of the HD mutation changes an individual's or couple's decision to start a family or to have more children. The purpose of this qualitative study was to examine reproductive decision-making in a sample of individuals at risk for HD who have chosen not to pursue genetic testing. PHAROS (Prospective Huntington At Risk Observational Study) is a multi-site study that aims to establish whether experienced clinicians can reliably determine the earliest clinical symptoms of HD in a sample of individuals at 50% risk who have chosen not to pursue genetic testing. Data for this article were obtained from unstructured open ended qualitative interviews of a subsample of individuals participating in the PHAROS project. Interviews were conducted at six PHAROS research sites across the United States. In this paper, the research team used qualitative descriptive methods to construct and explore reproduction decision-making in three groups of people: 1) those who knew of their risk and decided to have children; 2) those who had children before they knew of their risk, and 3) those who chose not to have children based on their risk. We discuss the delicate balance health care professionals and genetic counselors must maintain between the benefits of providing hope and the dangers of offering unrealistic expectations about the time in which scientific advances actually may occur.
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Toma de Decisiones , Predisposición Genética a la Enfermedad , Enfermedad de Huntington/fisiopatología , Reproducción , Niño , Humanos , Enfermedad de Huntington/genética , Enfermedad de Huntington/psicología , Mutación , Factores de RiesgoRESUMEN
BACKGROUND: The apolipoprotein E (APOE) genotype provides information on the risk of Alzheimer's disease, but the genotyping of patients and their family members has been discouraged. We examined the effect of genotype disclosure in a prospective, randomized, controlled trial. METHODS: We randomly assigned 162 asymptomatic adults who had a parent with Alzheimer's disease to receive the results of their own APOE genotyping (disclosure group) or not to receive such results (nondisclosure group). We measured symptoms of anxiety, depression, and test-related distress 6 weeks, 6 months, and 1 year after disclosure or nondisclosure. RESULTS: There were no significant differences between the two groups in changes in time-averaged measures of anxiety (4.5 in the disclosure group and 4.4 in the nondisclosure group, P=0.84), depression (8.8 and 8.7, respectively; P=0.98), or test-related distress (6.9 and 7.5, respectively; P=0.61). Secondary comparisons between the nondisclosure group and a disclosure subgroup of subjects carrying the APOE epsilon4 allele (which is associated with increased risk) also revealed no significant differences. However, the epsilon4-negative subgroup had a significantly lower level of test-related distress than did the epsilon4-positive subgroup (P=0.01). Subjects with clinically meaningful changes in psychological outcomes were distributed evenly among the nondisclosure group and the epsilon4-positive and epsilon4-negative subgroups. Baseline scores for anxiety and depression were strongly associated with post-disclosure scores of these measures (P<0.001 for both comparisons). CONCLUSIONS: The disclosure of APOE genotyping results to adult children of patients with Alzheimer's disease did not result in significant short-term psychological risks. Test-related distress was reduced among those who learned that they were APOE epsilon4-negative. Persons with high levels of emotional distress before undergoing genetic testing were more likely to have emotional difficulties after disclosure. (ClinicalTrials.gov number, NCT00571025.)
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Enfermedad de Alzheimer/genética , Apolipoproteína E4/genética , Predisposición Genética a la Enfermedad/psicología , Pruebas Genéticas/psicología , Revelación de la Verdad , Adulto , Anciano , Enfermedad de Alzheimer/psicología , Ansiedad/etiología , Distribución de Chi-Cuadrado , Depresión/etiología , Femenino , Asesoramiento Genético , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Estudios ProspectivosRESUMEN
Much of the qualitative research on Huntington disease has focused on the genetic testing aspects of HD. The overall purpose of this qualitative study was to gather information about the everyday experience of living with the risk of developing Huntington disease in a sample of individuals at risk for HD who have chosen not to pursue genetic testing. Data for this article was obtained from unstructured, open-ended qualitative interviews of a sample of people participating in the PHAROS study. PHAROS, the Prospective Huntington At-Risk Observational Study, is a multi-site study that aims to establish whether experienced clinicians can reliably determine the earliest clinical symptoms of Huntington disease in individuals at 50% risk for HD who have chosen not to undergo genetic testing. Interviews were conducted at six PHAROS research sites across the United States. In this paper, the research team used qualitative description to construct and explore two main themes: (1) careful concealment of risk as an act of self-preservation and (2) preserving hope.
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Enfermedad de Huntington/psicología , Adulto , Estudios de Cohortes , Femenino , Pruebas Genéticas , Humanos , Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/genética , Enfermedad de Huntington/fisiopatología , Masculino , Factores de RiesgoRESUMEN
Human biological materials (HBMs) are samples of blood, DNA, organs and tissues commonly obtained during routine surgical procedures or through direct donation by an individual. This article reviews four of the most pressing issues arising from the collection, storage, and use of HBMs in research: current regulations governing research with human subjects, misuse of genetic information, economic factors, and public knowledge.
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Sangre , ADN , Ética en Investigación , Ética , Manejo de Especímenes/ética , Ensayos Clínicos como Asunto/legislación & jurisprudencia , Privacidad Genética/ética , Privacidad Genética/legislación & jurisprudencia , Humanos , Consentimiento Informado/legislación & jurisprudencia , Investigación/legislación & jurisprudencia , Bancos de Tejidos/ética , Donantes de Tejidos/ética , Donantes de Tejidos/legislación & jurisprudencia , Conservación de Tejido/éticaRESUMEN
PURPOSE: Alzheimer's disease, for which one form of the apolipoprotein E (APOE) genotype is a risk factor, provides a paradigm in which to examine response to susceptibility testing for common, complex diseases. This study's main purposes were to estimate interest in such testing and to examine demographic predictors of study participation. METHODS: In this 3-site, randomized clinical trial (RCT), the intervention was a risk assessment program wherein genetic counselors educated adult children of AD patients about lifetime risk of disease based on their gender, family history, and APOE genotype. Two groups of participants were followed from initial contact to RCT enrollment: those who were systematically contacted through research registries, and those who were self-referred. RESULTS: Of 196 systematically contacted participants, 47, or 24%, progressed from initial contact to RCT enrollment. These participants were more likely to be below age 60 (adjusted OR = 3.83, P < 0.01) and college educated (adjusted OR = 3.48, P < 0.01). Of 179 self-referred participants, 115, or 64%, progressed from initial contact to RCT enrollment. Most self-referred participants had a college education and were female (79%). CONCLUSIONS: In the first RCT to examine genetic susceptibility testing for AD, uptake rates were sufficiently high to merit concern that future test demand may strain available education and counseling resources. Findings suggest that susceptibility testing for AD may be of particular interest to women, college educated persons, and persons below age 60.
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Enfermedad de Alzheimer/diagnóstico , Apolipoproteínas E/genética , Pruebas Genéticas , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Femenino , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The rapid expansion of information and knowledge of genetics has implications for the question of whether, and under what circumstances, information discovered in the course of genetic research should be conveyed to research participants and/or their relatives. The aim of this paper is to propose an ethically defensible solution to a specific case example illustrating this problem. To do this we reviewed the literature to find answers to the following three questions: (1) What do current regulations, guidelines, and commentary say about the disclosure of genetic risk information obtained through research to research participants? (2) What do current regulations, guidelines, and commentary say about the disclosure of genetic risk information obtained through research to the relatives of research subjects? and (3) What do current regulations, guidelines, and commentary say about the disclosure of genetic risk information obtained through research about former research participants who are now deceased? Our conclusion is that current U.S. federal guidelines governing the use of human subjects in research, as well as much of the current literature, do not adequately address the familial dimension inherent in genetic research, are virtually silent on the issue of sharing information of relevance to family members, and do not protect the deceased. It is our belief that this omission needs to be corrected and that explicit guidance on this issue needs to be provided to institutional review boards and researchers alike.
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Asesoramiento Genético/ética , Privacidad Genética/ética , Investigación Genética/ética , Pruebas Genéticas/ética , Revelación de la Verdad/ética , Asesoramiento Genético/normas , Enfermedades Genéticas Congénitas/diagnóstico , Enfermedades Genéticas Congénitas/genética , Privacidad Genética/normas , Pruebas Genéticas/normas , Humanos , Factores de RiesgoRESUMEN
In "The Ethical Justification for Minimal Paternalism in the Use of the Predictive Test for Huntington's Disease," David DeGrazia attempts to provide a rational analysis of the exclusion criteria and counseling requirements for predictive testing proposed by the Huntington's Disease Society of America (HDSA). The need for analysis is clear. These protocols and procedures for predictive testing for Huntington's disease (HD) are being used as models for testing programs for any number of genetic conditions. DeGrazia concludes that the HDSA guidelines are reasonable, a conclusion with which I agree. However, I believe that DeGrazia, by placing his analysis within the framework of autonomy versus paternalism, overlooks both the fundamental rationale for the testing procedures and the true barriers to testing.... The difficulties encountered during the testing process clearly demonstrated the failure of abstract principles to deal with real life.