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.

HDQLIFE: development and assessment of health-related quality of life in Huntington disease (HD).

PURPOSE: Huntington disease (HD) is a chronic, debilitating genetic disease that affects physical, emotional, cognitive, and social health. Existing patient-reported outcomes (PROs) of health-related quality of life (HRQOL) used in HD are neither comprehensive, nor do they adequately account for clinically meaningful changes in function. While new PROs examining HRQOL (i.e., Neuro-QoL-Quality of Life in Neurological Disorders and PROMIS-Patient-Reported Outcomes Measurement Information System) offer solutions to many of these shortcomings, they do not include HD-specific content, nor have they been validated in HD. HDQLIFE addresses this by validating 12 PROMIS/Neuro-QoL domains in individuals with HD and by using established PROMIS methodology to develop new, HD-specific content. METHODS: New item pools were developed using cognitive debriefing with individuals with HD, and expert, literacy, and translatability reviews. Existing item banks and new item pools were field tested in 536 individuals with prodromal, early-, or late-stage HD. RESULTS: Moderate to strong relationships between Neuro-QoL/PROMIS measures and generic self-report measures of HRQOL, and moderate relationships between Neuro-QoL/PROMIS and clinician-rated measures of similar constructs supported the validity of Neuro-QoL/PROMIS in individuals with HD. Exploratory and confirmatory factor analysis, item response theory, and differential item functioning analyses were utilized to develop new item banks for Chorea, Speech Difficulties, Swallowing Difficulties, and Concern with Death and Dying, with corresponding six-item short forms. A four-item short form was developed for Meaning and Purpose. CONCLUSIONS: HDQLIFE encompasses both validated Neuro-QoL/PROMIS measures, as well as five new scales in order to provide a comprehensive assessment of HRQOL in HD.

New measures to capture end of life concerns in Huntington disease: Meaning and Purpose and Concern with Death and Dying from HDQLIFE (a patient-reported outcomes measurement system).

PURPOSE: Huntington disease (HD) is an incurable terminal disease. Thus, end of life (EOL) concerns are common in these individuals. A quantitative measure of EOL concerns in HD would enable a better understanding of how these concerns impact health-related quality of life. Therefore, we developed new measures of EOL for use in HD. METHODS: An EOL item pool of 45 items was field tested in 507 individuals with prodromal or manifest HD. Exploratory and confirmatory factor analyses (EFA and CFA, respectively) were conducted to establish unidimensional item pools. Item response theory (IRT) and differential item functioning analyses were applied to the identified unidimensional item pools to select the final items. RESULTS: EFA and CFA supported two separate unidimensional sets of items: Concern with Death and Dying (16 items), and Meaning and Purpose (14 items). IRT and DIF supported the retention of 12 Concern with Death and Dying items and 4 Meaning and Purpose items. IRT data supported the development of both a computer adaptive test (CAT) and a 6-item, static short form for Concern with Death and Dying. CONCLUSION: The HDQLIFE Concern with Death and Dying CAT and corresponding 6-item short form, and the 4-item calibrated HDQLIFE Meaning and Purpose scale demonstrate excellent psychometric properties. These new measures have the potential to provide clinically meaningful information about end-of-life preferences and concerns to clinicians and researchers working with individuals with HD. In addition, these measures may also be relevant and useful for other terminal conditions.

Early-onset Alzheimer disease caused by a new mutation (V717L) in the amyloid precursor protein gene.

CONTEXT: Alzheimer disease is the most common form of dementia. Mutations in the genes amyloid precursor protein (APP), presenilin 1(PS1) and presenilin 2(PS2) have been found in early-onset familial forms of Alzheimer disease OBJECTIVE: To determine the cause of dementia in a family with early-onset illness. DESIGN, SETTING, AND PARTICIPANTS: A family with a history of dementia was referred to the Indiana Alzheimer Disease Center, Indianapolis. All the research in this study was done in a university or university hospital. The proband and her 4 siblings took part in the study. The proband, who is still alive, showed symptoms of Alzheimer disease at 38 years of age. Genomic DNA was obtained from blood samples of 5 family members. The APPandPS1genes of the proband were screened for mutations by amplification followed by direct sequencing. RESULTS: Sequence of exon 17 of the APPgene revealed a single nucleotide (guanine to cytosine) substitution in 1 allele, resulting in an amino acid change at codon 717 (valine to leucine). Each of the proband's siblings were tested for this mutation by direct sequencing. Two of the 4 were found to have the mutation; one of whom was recently clinically diagnosed at the age of 36 years. CONCLUSIONS: A novel mutation in the APPgene (V717L) has been found in a family with a history of dementia, beginning in the mid to late 30s. The age of onset in this family is earlier than most of the other families with Alzheimer disease who also have APPmutations. Arch Neurol. 2000.

Presymptomatic Genetic Testing with an APP Mutation in Early-Onset Alzheimer Disease: A Descriptive Study of Sibship Dynamics.

Early-onset Alzheimer disease (AD) accounts for only 5% of all cases of Alzheimer disease. To date, mutations in three different genes, the Amyloid precursor protein (APP), Presenilin 1 (PS1), and Presenilin 2 (PS2), have been identified as causative in early-onset AD, making predictive testing possible. Predictive testing for early-onset Alzheimer disease is a relatively new phenomenon. This paper describes the process of identifying a new mutation in the APP gene associated with early-onset AD, notifying family members, and offering participation in research as well as predictive testing. The goal is to share the complexities of predictive testing in a sibship newly identified as being at risk for an adult-onset, incurable neurodegenerative disease.

The clinical introduction of genetic testing for Alzheimer disease. An ethical perspective.

OBJECTIVE: Primary caregivers should be aware of recent progress in the genetics of Alzheimer disease (AD) and of the clinical and ethical considerations raised regarding the introduction of genetic testing for purposes of disease prediction and susceptibility (risk) analysis in asymptomatic individuals and diagnosis in patients who present clinically with dementia. This statement addresses arguments for and against clinical genetic testing. PARTICIPANTS: The 20 participants were selected by the investigators (S.G.P., T.H.M., A.B.Z., and P.J.W.) to achieve balance in the areas of genetics, counseling, ethics, and public policy, and to include leadership from related consensus projects. The consensus group met twice in closed meetings and carried on extensive correspondence over 2 years (1995-1997). The project was supported by the National Human Genome Research Institute of the National Institutes of Health. EVIDENCE: All 4 involved chromosomes were discussed in group meetings against a background of information from several focus group sessions with AD-affected families. The focus groups comprised volunteers identified by the Cleveland Area Chapter of the Alzheimer's Disease and Related Disorders Association and represented a variety of ethnic populations. CONSENSUS PROCESS: The first draft was written in April 1996 by the principal investigator (S.G.P.) after the consensus group had met twice. The draft was mailed to all consensus group members 3 times over 6 months for extensive response and redrafting by the principal investigator until all members were satisfied. CONCLUSIONS: Except for autosomal dominant early-onset families, genetic testing in asymptomatic individuals is unwarranted. Use of APOE genetic testing as a diagnostic adjunct in patients already presenting with dementia may prove useful but it remains under investigation. The premature introduction of genetic testing and possible adverse consequences are to be avoided.

Issues in genetic testing for susceptibility to alcoholism: lessons from Alzheimer's disease and Huntington's disease.

Evidence from family, twin, and adoption studies suggest a heritable basis for alcoholism. However, alcoholism is likely to be genetically heterogeneous, and any genetic connection is likely to be in the form of genes conferring an increased risk or susceptibility. In this study, we present the evidence for a genetic component for alcoholism, and examine the precedent for genetic testing and screening for genetic susceptibility using Huntington's disease and Alzheimer's disease as examples. Finally, we discuss the preparations that need to be made before taking any findings about the genetics of alcoholism from the research laboratory into the clinic.

Exploration of the effects of predictive testing for Huntington disease on intimate relationships.

The focus in predictive testing for Huntington disease is beginning to shift from individuals at risk to an examination of the effects on other relatives, particularly on spouses and partners. We examine the effects of participating in a predictive testing program for 25 couples. When assessed prior to testing, spouses were significantly more depressed than their at-risk partners. After pretest counseling, 6 (24%) of the couples chose not to pursue testing. At baseline, these 6 couples had significantly higher levels of psychological distress and marital dysfunction than couples who did choose to complete testing. Of the 19 couples completing testing, 5 received an increased risk result and 14 received a decreased risk result. Prior to testing, the partners of individuals who later received an increased risk result exhibited higher levels of marital distress. At 3- and 6-month follow-ups, high-risk couples were significantly more distressed than low-risk couples. These levels of distress improved somewhat at 9 months after testing, but began to climb again at 12 months. Individuals at increased risk were significantly more distressed at all points during follow-up as compared to individuals at low risk. No significant differences were found between the partners of high- and low-risk individuals at 3, 6, 9, and 12 months after disclosure.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychological and ethical considerations in screening for disease.

Coronary artery disease is the leading cause of death in the United States. Serum cholesterol is a widely used screening test to detect persons at high risk for coronary artery disease, including those with familial hypercholesterolemia. However, universal screening of currently healthy persons is not without risk. Previous experience in screening for sickle cell anemia and hypertension has shown that these risks include misunderstanding of test results, misdiagnosis, labeling, stigmatization, and decreased psychological well-being. Results of screening programs may be misused by industry or insurance companies to exclude individuals from positions or benefits. Consideration of these harms suggests that screening should not be implemented until certain safeguards are in place. Physicians and the public should be educated about the potential risks and benefits of screening. Screening tests should be accurate, reliable, valid, and of demonstrated sensitivity. Informed consent for screening should be obtained. Follow-up surveillance and recommended treatments, including dietary counseling and drug therapy, should be available to all individuals identified as being at high risk regardless of their socioeconomic status. Finally, procedures to protect the right to privacy of individuals and their families should be implemented well in advance of the actual screening.

Reluctance to undergo predictive testing: the case of Huntington disease.

The development of a presymptomatic test for Huntington Disease (HD) has enabled some persons at risk to determine whether or not they are gene carriers. The purpose of this study was to explore the reasons why those at risk choose not to be tested in a situation where testing is available and most of the test-associated costs are covered by state funding. Subjects were also asked their levels of knowledge about testing, attitudes towards aspects of the testing protocols, and intentions towards testing once the gene for HD is found. Sixty-six individuals at risk for HD who had chosen not to be tested completed a mailed questionnaire. The most important reasons for not being tested were increased risk to children if one was found to be a gene carrier, absence of an effective cure, potential loss of health insurance, financial costs of testing, and the inability to "undo" the knowledge. Individuals comprising this sample were quite knowledgeable about predictive testing. Most supported the availability of testing despite the lack of a cure, the need for special counseling prior to testing, and the idea that testing should be a voluntary decision. Most said they would take the test if a treatment was available, if the mechanics of the test were simplified, or if the test was 100% accurate. The risk to relatives, lack of treatment or cure, fear of losing one's health insurance, and the accuracy of the information to be gained from testing are important factors in the decision not to be tested.

Presymptomatic testing for huntington diseases: Recommendations for counseling.

The discovery of a genetic marker linked to the Huntington disease (HD) gene made it possible to perform presymptomatic genetic testing for this late onset disorder. The first two pilot research programs in the United States, at Massachusetts General Hospital and Johns Hopkins Hospital, began offering testing in the Fall of 1986. Twenty-three centers are now offering this testing as part of their clinical service. As testing for this and other late onset diseases becomes more widespread, it is important to assess what we have learned about offering this test to those at risk. This article presents recommendations based on the author's 5 years of experience offering presymptomatic testing for HD in order to alert counselors to the complexities of offering this type of service.

Knowledge, attitude, and the decision to be tested for Huntington's disease.

In September 1986, the Baltimore Huntington's Disease Project initiated a voluntary program of presymptomatic genetic testing for Huntington's Disease (HD). Forty-seven persons at 50% risk for HD attended one of two educational sessions designed to educate them about the test. At the beginning and end of each session, subjects completed the Affect Adjective Checklist and a set of questions assessing knowledge about and attitude toward presymptomatic testing. As a result of attending an educational session, subjects learned more about presymptomatic testing, and their attitude towards finding out whether they had the marker for the HD gene became more favorable. Fewer people requested genetic testing than expected. Those who later chose to undergo genetic testing had a more favorable attitude at both the beginning and at the end of the educational session. The significance of these data for genetic counselors is discussed.

Presymptomatic diagnosis of delayed-onset disease with linked DNA markers. The experience in Huntington's disease.

Clinical medicine in the 21st century is almost certain to include wide-scale use of molecular genetic diagnostic tests. In September 1986, The Johns Hopkins University School of Medicine initiated a voluntary program of presymptomatic genetic testing for Huntington's disease for persons at 50% risk. DNA analyses using the D4S10 (G8), D4S43, and D4S95 locus probes have been performed for 55 people. Twelve of the tests have yielded positive results, 30 were negative, and 13 were uninformative. Initial reactions ranged from joy and relief to disappointment, sadness, and demoralization. Thus far, there have been no severe depressive reactions. Although the sample size is small, our data suggest that people who receive genetic test results cope well, at least over the short term, when the testing is performed in a clinical context that includes education, pretest counseling, psychological support, and regular follow-up.

Preparatory interval influences on reaction-time of elderly adults.

The influence of regularity of preparatory interval (PI) on simple reaction-time (RT) in elderly persons was studied in a sample of 25 women between 65 and 88 years of age. RTs to regular and variable PIs of 1, 3, 7, 9, and 13 seconds were compared using Steffy's embedded isotemporal blocks method. The advantage of PI regularity was lost at 13 sec, where performance was faster for irregular trials. The RT-PI functions were similar to those found by Botwinick and his associates who used Shakow's paradigm, even though overall RT was slower in this sample. The similarity of results across the two paradigms suggest that the point of RT function crossover is interval dependent and unrelated to response latency in elderly adults.