1
|
Nance MA. Genetic counseling and testing for Huntington's disease: A historical review. Am J Med Genet B Neuropsychiatr Genet 2017; 174:75-92. [PMID: 27174011 DOI: 10.1002/ajmg.b.32453] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/15/2016] [Indexed: 12/26/2022]
Abstract
This manuscript describes the ways in which genetic counseling has evolved since John Pearson and Sheldon Reed first promoted "a genetic education" in the 1950s as a voluntary, non-directive clinical tool for permitting individual decision making. It reviews how the emergence of Huntington's disease (HD) registries and patient support organizations, genetic testing, and the discovery of a disease-causing CAG repeat expansion changed the contours of genetic counseling for families with HD. It also reviews the guidelines, outcomes, ethical and laboratory challenges, and uptake of predictive, prenatal, and preimplantation testing, and it casts a vision for how clinicians can better make use of genetic counseling to reach a broader pool of families that may be affected by HD and to ensure that genetic counseling is associated with the best levels of care. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Martha A Nance
- Struthers Parkinson's Center, Golden Valley, Minnesota.,Hennepin County Medical Center, Minneapolis, Minnesota
| |
Collapse
|
2
|
|
3
|
Abstract
AbstractA significant minority of cases of Huntington's disease commence before the age of 20 years and these juvenile cases are more likely to demonstrate paternal transmission and a clinical picture dominated by rigidity. Genetic research and positron emission tomography may make early diagnosis easier but predictive testing in childhood is replete with serious problems. There is no specific treatment for this fatal disorder. Juvenile Huntington's disease has a similar pathology and biochemistry to the adult condition despite a shorter course and certain clinical differences, such as rigidity and convulsions. Racial differences are explored.
Collapse
|
4
|
Voracek M, Haubner T, Fisher ML. Recent Decline in Nonpaternity Rates: A Cross-Temporal Meta-Analysis. Psychol Rep 2008; 103:799-811. [DOI: 10.2466/pr0.103.3.799-811] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
5
|
|
6
|
Abstract
The Huntington disease gene was mapped to human chromosome 4p in 1983 and 10 years later the pathogenic mutation was identified as a CAG-repeat expansion. Our current understanding of the molecular pathogenesis of Huntington disease could never have been achieved without the recent progress in the field of molecular genetics. We are now equipped with powerful genetic models that continue to uncover new aspects of the pathogenesis of Huntington disease and will be instrumental for the development of therapeutic approaches for this disease.
Collapse
Affiliation(s)
- Gillian P Bates
- Department of Medical and Molecular Genetics, GKT School of Medicine, King's College London, 8th Floor Guy's Tower, Guy's Hospital, London SE1 9RT, United Kingdom.
| |
Collapse
|
7
|
McRae CA, Diem G, Yamazaki TG, Mitek A, Wszolek ZK. Interest in genetic testing in pallido-ponto-nigral degeneration (PPND): a family with frontotemporal dementia with Parkinsonism linked to chromosome 17. Eur J Neurol 2001; 8:179-83. [PMID: 11284997 DOI: 10.1046/j.1468-1331.2001.00198.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The specific mutation on the tau gene responsible for a neurodegenerative disease known as pallido-ponto-nigral degeneration (PPND) was recently located. PPND family members are at risk for an autosomal dominant form of frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). This study investigated whether individuals in this family would consider presymptomatic genetic testing. Surveys were sent to 66 at-risk individuals in the family; replies were received from 20 (30%). Family members were asked if they would consider having testing now or in the future, and to indicate their reasons for and against proceeding with testing. Fifty per cent (n=10) of those who were at risk and who responded indicated they would consider testing now, and 55% (n=11) would think about it in the future. The most frequently cited reasons to proceed with testing were to 'collaborate with research' (70%) and to 'know if my children are at risk' (45%). The most frequently cited reason not to pursue testing was 'I can enjoy my life more fully by not knowing' (50%). Results suggest that interest in determining whether they will manifest PPND is generally low among at-risk members of this family, despite wide support and participation in other research studies.
Collapse
Affiliation(s)
- C A McRae
- University of Denver, Denver, Colorado, USA
| | | | | | | | | |
Collapse
|
8
|
Harper PS, Lim C, Craufurd D. Ten years of presymptomatic testing for Huntington's disease: the experience of the UK Huntington's Disease Prediction Consortium. J Med Genet 2000; 37:567-71. [PMID: 10922381 PMCID: PMC1734651 DOI: 10.1136/jmg.37.8.567] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Data on all presymptomatic genetic tests for Huntington's disease (HD) in the UK have been collected over the 10 year period since testing became available as a service. A total of 2937 completed tests have been performed up to the end of 1997, 2502 based on specific mutation testing, feasible since late 1993.A total of 93.1% of these were at 50% prior risk, with a significant excess of females (58.3%); 41.4% of results were abnormal or high risk, including 29.4% in subjects aged 60 or over. The trend in test numbers has currently levelled out at around 500 per year. Almost all presymptomatic tests are carried out in National Health Service genetics centres, with a defined genetic counselling protocol and with availability now in all regions of the UK. The introduction and establishment of HD presymptomatic testing shows that this form of predictive medicine for Mendelian disorders can be successfully incorporated into National Health Service structures. The comprehensive collection of simple data allows trends in demand and outcomes to be monitored and has also been the foundation for more detailed specific studies. A comparable approach to data collection in other genetic disorders will be important as presymptomatic testing becomes more generally feasible.
Collapse
Affiliation(s)
- P S Harper
- Institute of Medical Genetics, University of Wales College of Medicine, Cardiff, UK.
| | | | | |
Collapse
|
9
|
Maat-Kievit A, Vegter-van der Vlis M, Zoeteweij M, Losekoot M, van Haeringen A, Kanhai H, Roos R. Experience in prenatal testing for Huntington's disease in The Netherlands: procedures, results and guidelines (1987-1997). Prenat Diagn 1999. [DOI: 10.1002/(sici)1097-0223(199905)19:5<450::aid-pd568>3.0.co;2-l] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
10
|
Houlihan GD. The evaluation of the 'stages of change' model for use in counselling client's undergoing predictive testing for Huntington's disease. J Adv Nurs 1999; 29:1137-43. [PMID: 10320497 DOI: 10.1046/j.1365-2648.1999.00992.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nurses are increasingly working in new and novel situations which may be outside the realms of traditional nursing practice. Therefore when evaluating theories and models that may be utilized in these situations it may be necessary to look beyond established nursing theories and concepts. This paper therefore attempts to evaluate Prochaska & DiClemente's (1983) stages of change model for its goodness of fit when counselling people as part of the predictive testing programme for Huntington's disease. The model demonstrates that in order to provide effective communication it is important to recognize the particular stage a client is at in his/her decision-making process concerning predictive testing. The relevance of the model to generic genetic counselling in nursing practice is discussed and the importance of stage-matched nursing interventions is emphasized. The model's non-reliance on the medical model or the concept of illness means that it may also be a useful model when applied to other nursing situations.
Collapse
Affiliation(s)
- G D Houlihan
- School of Nursing and Midwifery, University of Glamorgan, South Wales, UK
| |
Collapse
|
11
|
Ross CA, Margolis RL, Rosenblatt A, Ranen NG, Becher MW, Aylward E. Huntington disease and the related disorder, dentatorubral-pallidoluysian atrophy (DRPLA). Medicine (Baltimore) 1997; 76:305-38. [PMID: 9352736 DOI: 10.1097/00005792-199709000-00001] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- C A Ross
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2196, USA
| | | | | | | | | | | |
Collapse
|
12
|
van 't Spijker A, ten Kroode HF. Psychological aspects of genetic counselling: a review of the experience with Huntington's disease. PATIENT EDUCATION AND COUNSELING 1997; 32:33-40. [PMID: 9355570 DOI: 10.1016/s0738-3991(97)00066-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Presymptomatic DNA-testing for adult-onset diseases has serious psychological consequences. Here the psychological consequences of presymptomatic DNA-testing for Huntington's disease are reviewed. Both carriers and non-carriers experience emotional reactions after disclosure of their test result. However, up to today no long-term adverse emotional consequences have been revealed. Future research on other adult-onset genetic diseases should provide information about the reactions of children. In genetic counselling, attention should be paid to the reactions of people with a decreased risk. Genetic counselling must focus on the whole family and not on the individual applicant.
Collapse
Affiliation(s)
- A van 't Spijker
- Department of Medical Psychology and Psychotherapy, Erasmus University Rotterdam, The Netherlands
| | | |
Collapse
|
13
|
Abstract
Huntington's disease is an autosomal dominant neuropsychiatric disorder which usually afflicts people with dependents. Psychiatric disorders figure prominently in the differential diagnosis, and may complicate the clinical picture, sometimes even antedating the onset of neurological signs. Diagnosis is still usually clinical, for which some knowledge of the disease is required. Positron emission tomography, where available, can assist in early detection. Recent scientific breakthroughs have considerably improved the accuracy of predictive genetics, and the psychological outcome of such testing may be better than previously, but considerable ethical dilemmas have yet to be fully addressed. Genetic treatment is being considered. Drug treatments offer crude symptomatic improvement. Counselling and support services are essential, as are voluntary self-help organisations. Specific day and inpatient facilities are sparse.
Collapse
Affiliation(s)
- B O'Shea
- Consultant Psychiatrist, Newcastle Hospital, Greystones, Ireland
| |
Collapse
|
14
|
Michie S, McDonald V, Bobrow M, McKeown C, Marteau T. Parents' responses to predictive genetic testing in their children: report of a single case study. J Med Genet 1996; 33:313-8. [PMID: 8730287 PMCID: PMC1050581 DOI: 10.1136/jmg.33.4.313] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
There is a widely held view among health professionals that predictive genetic testing of children for late onset diseases is not desirable clinical practice. Yet, little is known about the views of parents, or their responses, to predictive genetic testing in their children. Since such testing is being carried out in some genetic centres, the opportunity was taken to conduct a single case study of the parents of 2 and 4 year old sisters who were tested for the gene for familial adenomatous polyposis. Interviews before testing, after, and 15 months later showed a stable attitude, that parental responsibility included making decisions about such testing, and that the role of health professionals should be one of information giving rather than decision making. These parents had no regrets about having their children tested and reported no changes in their behaviour towards either the child who tested positively or the child who tested negatively. Using standardised scales, mood was found to be within the normal range both before and after testing in the mother and father. This case study is a first step towards systematic empirical studies determining the consequences of acquiescing to parents' requests for genetic testing in their children.
Collapse
Affiliation(s)
- S Michie
- Psychology and Genetics Research Group, United Medical School, Guy's Hospital, London, UK
| | | | | | | | | |
Collapse
|
15
|
|
16
|
Ethical and social issues in presymptomatic testing for Huntington's disease: a European Community collaborative study. European Community Huntington's Disease Collaborative Study Group. J Med Genet 1993; 30:1028-35. [PMID: 8133502 PMCID: PMC1016639 DOI: 10.1136/jmg.30.12.1028] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
An analysis of social and ethical aspects of presymptomatic testing for Huntington's disease has been carried out, based on data on linked DNA markers, from four major testing centres in different European Community countries (Belgium, Italy, Netherlands, and United Kingdom). Information was available on 603 applicants, with 213 final results given, of which 32% gave an increased risk. A series of specific issues and problems were documented systematically for all applicants, results being given on frequency of occurrence and illustrated by individual case histories. The principal issues could be grouped as problems of inappropriate referral, problems involving relatives, and problems relating to disclosure of results. At least one important problem was encountered in 46% of applicants, emphasising the importance of expert counselling, preparation, and support of applicants, and of close liaison between clinical, counselling, and laboratory staff. The extensive and detailed information available for Huntington's disease from this and other studies will be of considerable value in relation to genetic testing for other late onset genetic disorders and will be even more relevant to Huntington's disease now that specific mutation analysis is possible for this disorder.
Collapse
|
17
|
Presymptomatic testing for Huntington's disease: a world wide survey. The World Federation of Neurology Research Group on Huntington's Disease. J Med Genet 1993; 30:1020-2. [PMID: 8133500 PMCID: PMC1016637 DOI: 10.1136/jmg.30.12.1020] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
World wide data on presymptomatic testing for Huntington's disease using closely linked DNA markers show that 1479 persons at risk received completed test results up to the end of 1991. Testing has been carried out in 19 countries, with at least 88 centres involved, and numbers have levelled off after a peak in 1990. Only 5% of those at risk have been tested in six countries with the longest established programmes. Continued monitoring of international data will be of value in assessing the spread and impact of genetic testing, not only for Huntington's disease, but for other serious genetic disorders of later life.
Collapse
|
18
|
|
19
|
Harper PS. Research samples from families with genetic diseases: a proposed code of conduct. BMJ (CLINICAL RESEARCH ED.) 1993; 306:1391-4. [PMID: 8518608 PMCID: PMC1677780 DOI: 10.1136/bmj.306.6889.1391] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Research on samples from families with genetic disease underlies many of the major advances that are occurring in medical genetics. But ethical and practical problems may arise when samples from relatives who are healthy but at risk are included in such studies. In particular, new molecular tests for specific gene mutations may result in the detection of a genetic defect in relatives who had neither expected this possibility nor given specific consent to such testing. Family members at risk should not be included in such studies unless strictly necessary, and in such cases specific consent should be obtained and information should be given about the implications of an abnormal result of a test. This is particularly important when stored samples from previous studies without such implications are being reused and is also relevant to the genetic testing of samples taken primarily for epidemiological studies of disorders when only a small proportion of cases is thought to be genetic in origin. There is a need for guidelines to protect both subjects and investigators in a field which is spreading rapidly and involving many clinical and laboratory research workers previously unfamiliar with genetic testing.
Collapse
Affiliation(s)
- P S Harper
- Institute of Medical Genetics, University of Wales College of Medicine, Heath Park, Cardiff
| |
Collapse
|
20
|
Lazarou LP, Meredith AL, Myring JM, Tyler A, Morris M, Ball DM, Harper PS. Huntington's disease: predictive testing and the molecular genetics laboratory. Clin Genet 1993; 43:150-6. [PMID: 8098998 DOI: 10.1111/j.1399-0004.1993.tb04441.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We describe the laboratory-related aspects of a series of 40 completed presymptomatic tests for Huntington's disease, using linked DNA markers. Pedigree structure and marker heterozygosity are shown to be important factors, both in the number of laboratory analyses required to give an informative situation and the residual uncertainty of the final estimate. Specific problems encountered by the testing laboratory are described, with possible ways of avoiding them, and the close links required between laboratory and clinical staff are emphasised.
Collapse
Affiliation(s)
- L P Lazarou
- Institute of Medical Genetics, University of Wales College of Medicine, Cardiff, UK
| | | | | | | | | | | | | |
Collapse
|
21
|
Thies U, Zühlke C, Bockel B, Schröder K. Prenatal diagnosis of Huntington's disease (HD): experiences with six cases and PCR. Prenat Diagn 1992; 12:1055-61. [PMID: 1287641 DOI: 10.1002/pd.1970121212] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the course of a 2-year predictive testing programme for Huntington's disease (HD), six couples from a total of 52 applicants requested prenatal testing. In each case, the pregnancy was in the first or second trimester when the couples were referred for DNA diagnosis. In five cases, exclusion testing was offered; in one case, a person at risk with an increased risk of being a gene carrier requested prenatal diagnosis. In all cases, informative markers for prenatal testing could be determined. Whenever possible, the newer technique of polymerase chain reaction (PCR) for D4S125 was applied to perform rapid prenatal diagnosis. Two couples withdrew before chorionic villus sampling was undertaken; prenatal diagnosis was completed in the remaining four cases. After exclusion testing, two pregnancies were determined to have an increased risk and two fetuses to have a low risk of being HD gene carriers.
Collapse
Affiliation(s)
- U Thies
- Institute of Human Genetics, University of Göttingen, Germany
| | | | | | | |
Collapse
|
22
|
Abstract
Public and professional concern associated with the idea of genetic screening has generated numerous publications on the ethics of genetic screening (e.g. 1-4). Concerns revolve around inadequate consultation before screening is carried out, the unearthing of worrying risks, the use of genetic information in ways that could be disadvantageous to the person involved, stigma, and a phenomenon known as the 'technological imperative', which means that simply because a technology is available there is a tendency to use it. Most reports agree that, in practice, the main ethical problems are likely to involve screening for risk of common diseases of adult life, because of the possible impact on a person's healthy self-image, implications for health and life insurance, and the possibility of commercial exploitation of people who know themselves to be vulnerable. In this paper I do not propose to address these issues directly. I have been invited to discuss this subject as a clinician involved with genetic screening, counselling and prenatal diagnosis for the haemoglobin disorders, the most common serious human recessively inherited diseases. Since we are scientists, any recommendations we make should be based on experience: my aim is to show that experience is often surprising, and that it is often possible to meet public concerns by taking quite simple practical steps.
Collapse
Affiliation(s)
- B Modell
- Department of Obstetrics and Gynaecology, University College London, UK
| |
Collapse
|
23
|
|
24
|
Tyler A, Morris M, Lazarou L, Meredith L, Myring J, Harper P. Presymptomatic testing for Huntington's disease in Wales 1987-90. Br J Psychiatry 1992; 161:481-8. [PMID: 1393334 DOI: 10.1192/bjp.161.4.481] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Between 1987 and 1990 a large series of at-risk individuals has been referred to our Huntington's disease (HD) presymptomatic testing programme. A detailed protocol for assessment and counselling has been followed. Out of 238 serious inquiries, 36% were potentially suitable for the testing programme, but 19% chose not to continue. Reasons for exclusion included the presence of clinical features of HD and being under the age of 18 years. Out of 40 final results given to 38 individuals, 23 indicated a lowered risk, 11 an increased risk, while five results were uninformative, two of these becoming informative on repeat testing. This series contained more women than men, and was disproportionately from the higher socio-economic groups. Motives for requesting a test principally related to child-bearing, informing existing children, and planning for the future. No significant psychiatric symptoms have been reported in the short term, but difficult counselling problems were presented by the high proportion of applicants who already showed clinical signs of HD. It is concluded that a detailed counselling protocol is essential in testing for HD, as many applicants are ill-prepared; this will assume even greater importance when the HD gene is identified and a test for specific mutations is available. The experience of presymptomatic testing for HD provides important general lessons which are likely to be applicable to other inherited neurological and psychiatric disorders.
Collapse
Affiliation(s)
- A Tyler
- Institute of Medical Genetics, University of Wales College of Medicine, Heath Park, Cardiff
| | | | | | | | | | | |
Collapse
|
25
|
Reardon W, Floyd JL, Myring J, Lazarou LP, Meredith AL, Harper PS. Five years experience of predictive testing for myotonic dystrophy using linked DNA markers. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 43:1006-11. [PMID: 1415325 DOI: 10.1002/ajmg.1320430618] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report on a 5 year experience in providing presymptomatic and prenatal molecular diagnostic services for myotonic dystrophy, using closely linked markers, representing 235 completed results in 161 families. Only 10 analyses (4.3%) proved uninformative, but a further 5 requests (1.9%) could not be reported because of uncertainty in clinical status. Seven of 81 (8.6%) patients considered to be at low risk on clinical grounds were found to be at high risk of carrying the gene. The importance of interpreting molecular results in conjunction with clinical findings is emphasised by the illustrative examples provided. Careful clinical examination and appropriate investigation remain a cornerstone of diagnosis in myotonic dystrophy and are crucial if errors in assigning genotype status by molecular means are to be minimised.
Collapse
Affiliation(s)
- W Reardon
- Institute of Medical Genetics, University Hospital of Wales, Heath Park, Cardiff
| | | | | | | | | | | |
Collapse
|
26
|
Harper PS, Newcombe RG. Age at onset and life table risks in genetic counselling for Huntington's disease. J Med Genet 1992; 29:239-42. [PMID: 1533876 PMCID: PMC1015921 DOI: 10.1136/jmg.29.4.239] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Age related genetic risk data for carrying the gene for Huntington's disease in relatives at risk, based on a previously documented life table approach, are presented in a form allowing ready access for use in genetic counselling. Figures are given for first degree relatives and for second degree relatives showing varying age combinations of consultand and intervening parent at risk. Data are also given for the risk of developing Huntington's disease over varying finite periods in relation to age. The availability of this information in tabular form should help those involved in genetic counselling for this disorder in providing accurate risk estimates to relatives; the data are also of importance for combination with genotype information in predictive testing.
Collapse
Affiliation(s)
- P S Harper
- Institute of Medical Genetics, University of Wales College of Medicine, Cardiff
| | | |
Collapse
|
27
|
Nance MA, Leroy BS, Orr HT, Parker T, Rich SS, Heston LL. Protocol for genetic testing in Huntington disease: three years of experience in Minnesota. AMERICAN JOURNAL OF MEDICAL GENETICS 1991; 40:518-22. [PMID: 1836107 DOI: 10.1002/ajmg.1320400431] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Molecular genetic testing for Huntington disease (HD) by linkage analysis of DNA markers close to the HD gene has been possible since the mid-1980s. Because of ethical and practical concerns about this kind of testing, most groups performing the test in the past have operated under lengthy research protocols designed to assess the psychological morbidity of the presymptomatic diagnosis of a fatal disease. Our approach to HD testing is service-oriented, and our testing process has been designed to be flexible, to meet the varying needs of our patients. Between 1988 and 1990, 87 inquiries about the test have been received; 22 inquiries had family structures which were unsuitable for linkage analysis. Eleven of the 37 individuals who entered the testing program have not completed it. Of 19 patients who have received DNA results, seven received an increased risk of carrying the HD gene, and ten, a decreased risk. For two additional individuals, nonpaternity resulted in a negligible risk for HD. Several of those consulted, or their spouses, have had continuing outpatient counseling since completing the test; none have required hospitalization. Our short-term results indicate that molecular genetic testing for HD can be performed safely in a clinical setting using our protocol. As molecular genetic testing for HD and other diseases moves out of research centers and into clinics, clinicians must devise practical strategies for providing the medical, genetic, and psychological services needed for the growing number of individuals who will seek such testing.
Collapse
Affiliation(s)
- M A Nance
- Department of Pediatrics, University of Minnesota, Minneapolis
| | | | | | | | | | | |
Collapse
|
28
|
Affiliation(s)
- P S Harper
- Institute of Medical Genetics, University of Wales College of Medicine, Cardiff, UK
| | | |
Collapse
|
29
|
Harper PS, Morris MJ, Tyler A. Genetic testing for Huntington's disease. BMJ (CLINICAL RESEARCH ED.) 1990; 300:1089-90. [PMID: 2140520 PMCID: PMC1662789 DOI: 10.1136/bmj.300.6732.1089] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- P S Harper
- Institute of Medical Genetics, University of Wales College of Medicine, Cardiff
| | | | | |
Collapse
|
30
|
|