Two Decades of Huntington Disease Testing: Patient’s Demographics and Reproductive Choices

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

Factors related to genetic testing in adults at risk for Huntington disease: the prospective Huntington at-risk observational study (PHAROS)

Huntington disease (HD) is a late onset ultimately fatal neurodegenerative disorder caused by a cytosine-adenine-guanine ( CAG) triplet repeat expansion in the Huntingtin gene which was discovered in 1993. The PHAROS study is a unique observational study of 1001 individuals at risk for HD who had not been previously tested for HD and who had no plans to do so. In this cohort, 104 (10%) individuals changed their minds and chose to be tested during the course of the study but outside of the study protocol. Baseline behavioral scores, especially apathy, were more strongly associated with later genetic testing than motor and chorea scores, particularly among subjects with expanded CAG repeat length. In the CAG expanded group, those choosing to be tested were older and had more chorea and higher scores on the behavioral section of the unified Huntington's disease rating scale at baseline than those not choosing to be tested. Following genetic testing, 56% of subjects with CAG < 37 had less depression when compared to prior to testing, but depression generally stayed the same or increased for 64% of subjects in the expanded group. This finding suggests that approaches to testing must continue to be cautious, with appropriate medical, psychological and social support

Erratum to: Benchmarks for ethically credible partnerships between industry and academic health centers: beyond disclosure of financial conflicts of interest.

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

[(11)C]PiB PET in Gerstmann-Sträussler-Scheinker disease

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

Clinical use of amyloid-positron emission tomography neuroimaging: Practical and bioethical considerations

Until recently, estimation of β-amyloid plaque density as a key element for identifying Alzheimer's disease (AD) pathology as the cause of cognitive impairment was only possible at autopsy. Now with amyloid-positron emission tomography (amyloid-PET) neuroimaging, this AD hallmark can be detected antemortem. Practitioners and patients need to better understand potential diagnostic benefits and limitations of amyloid-PET and the complex practical, ethical, and social implications surrounding this new technology. To complement the practical considerations, Eli Lilly and Company sponsored a Bioethics Advisory Board to discuss ethical issues that might arise from clinical use of amyloid-PET neuroimaging with patients being evaluated for causes of cognitive decline. To best address the multifaceted issues associated with amyloid-PET neuroimaging, we recommend this technology be used only by experienced imaging and treating physicians in appropriately selected patients and only in the context of a comprehensive clinical evaluation with adequate explanations before and after the scan

Decreased body mass index in the preclinical stage of autosomal dominant Alzheimer\u27s disease

The relationship between body-mass index (BMI) and Alzheimeŕs 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 Aβ 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

Characterizing neurodegeneration in the human connectome: a network science study of hereditary diffuse leukoencephalopathy with spheroids

poster abstractAbstract The effect of white matter neurodegeneration on the human connectome and its functional implications is an important topic with clinical applicability of advanced brain network analysis. The aim of this study was to evaluate integration and segregation changes in structural connectivity (SC) that arise as consequence of white matter lesions in hereditary diffuse leukoencephalopathy with spheroids (HDLS). Also, we assessed the relationship between HDLS induced structural changes and changes in restingstate functional connectivity (rsFC). HDLS is a rare autosomal dominant neurodegenerative disorder caused by mutations in the CSF1R gene. HDLS is characterized by severe white matter damage leading to prominent subcortical lesions detectable by structural MRI. Spheroids, an important feature of HDLS, are axonal swellings indicating damage. HDLS causes progressive motor and cognitive decline. The clinical symptoms of HDLS are often mistaken for other diseases such as Alzheimer’s disease, frontotemporal dementia, atypical Parkinsonism or multiple sclerosis. Our study is focused on the follow-up of two siblings, one being a healthy control (HC) and the other one being an HDLS patient. In this study, deterministic fiber-tractography of diffusion MRI with multi-tensor modeling was used in order to obtain reliable and reproducible SC matrices. Integration changes were measured by means of SC shortest-paths (including distance and number of edges), whereas segregation and community organization were measured by means of a multiplex modularity analysis on the SC matrices. Additionally, rsFC was modeled using state of the art preprocessing methods including motion regressors and scrubbing. This allowed us to characterize functional changes associated to the disease. Major integration disruption involved superior frontal (L,R), caudal middle frontal (R), precentral (L,R), inferior parietal (R), insula (R) and paracentral (L) regions. Major segregation changes were characterized by the disruption of a large bilateral module that was observed in the HC that includes the frontal pole (L,R), medial orbitofrontal (L,R), rostral middle frontal (L), superior frontal (L,R), precentral (L,R), paracentral (L,R), rostral anterior cingulate (L,R), caudal anterior cingulate (L,R), posterior cingulate (L,R), postcentral (L), precuneus (L,R), lateral orbitofrontal (R) and parsorbitalis (R). The combination of tractography and network analysis permitted the detection and characterization of profound cortical to cortical changes in integration and segregation associated with HDLS white matter lesions and its relationship with rsFC. Our preliminary findings suggest that advanced network analytic approaches show promising sensitivity to known white matter pathology and progression. Further Indiana Alzheimer Disease Center Symposium. March 6, 2015. research is needed to address the specificity of network profiles for differentiation among white matter pathologies and diseases