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Wadrup F, Holden S, MacLeod R, Miedzybrodzka Z, Németh AH, Owens S, Pasalodos S, Quarrell O, Clarke AJ. A case-note review of continued pregnancies found to be at a high risk of Huntington's disease: considerations for clinical practice. Eur J Hum Genet 2019; 27:1215-1224. [PMID: 30890781 DOI: 10.1038/s41431-019-0375-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 12/17/2018] [Accepted: 02/02/2019] [Indexed: 11/09/2022] Open
Abstract
Huntington's disease (HD) is a severe neurodegenerative condition that impacts the whole family. Prenatal diagnosis by direct or exclusion testing is available for couples at risk of transmitting HD to their children. An ethical problem can arise after prenatal diagnosis for HD if a known 'high risk' pregnancy is continued to term: international guidelines emphasise that this situation should be avoided where possible, as it removes the resulting child's future right to make an informed, autonomous decision about predictive testing. The UK Huntington's Disease Predictive Testing Consortium recorded 21 pregnancies that were tested, identified as high-risk and then continued. In this qualitative study, health professionals reviewed the case notes of 15 of these pregnancies. This analysis generated guidelines for clinical practice. It is recommended that practitioners: (i) remind couples of the long-term consequences of continuing a high risk pregnancy, (ii) ensure couples understand the information provided, (iii) collaborate closely with other professionals involved in the couple's prenatal care, (iv) prepare couples for the procedural aspects of prenatal diagnosis and a possible termination of pregnancy, (v) allow time for in-depth pre-test counselling, (vi) explain the rationale for only making prenatal diagnosis available subject to conditions, whilst allowing for human ambivalence and acknowledging that these 'conditions' cannot be enforced, (vii) monitor the whole clinical process to ensure that it works 'smoothly', (viii) recommend couples do not disclose the result of the prenatal test to protect the confidentiality and autonomy of the future 'high-risk' child, and (ix) offer on-going contact and support.
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Affiliation(s)
- Felicity Wadrup
- East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Simon Holden
- East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Academic Department of Medical Genetics, Addenbrooke's Treatment Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Rhona MacLeod
- Division of Evolution and Genomic Sciences, School of Biological Science, University of Manchester, Manchester, UK.,Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - Zosia Miedzybrodzka
- University of Aberdeen College of Life Sciences and Medicine, Division of Applied Medicine, Aberdeen, UK.,NHS Grampian Clinical Genetics Service, Medical Genetics, Aberdeen, UK
| | - Andrea H Németh
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Shan Owens
- Hywel Dda UHB (Milford Haven Health Care Centre, Yorke St, Milford Haven, Pembrokeshire, Wales, UK.,All Wales Medical Genetics Service, University Hospital of Wales, Cardiff, UK
| | - Sara Pasalodos
- Genomic Medicine Unit, Navarrabiomed, Biomedical Research Centre, Pamplona, Spain
| | - Oliver Quarrell
- Department of Clinical Genetics, Sheffield Children's Hospital, OPD II Northern General Hospital, Herries Road, Sheffield, UK
| | - Angus J Clarke
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK.
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Cruz-Mariño T, Vázquez-Mojena Y, Velázquez-Pérez L, González-Zaldívar Y, Aguilera-Rodríguez R, Velázquez-Santos M, Estupiñán-Rodríguez A, Laffita-Mesa JM, Almaguer-Mederos LE, Paneque M. SCA2 predictive testing in Cuba: challenging concepts and protocol evolution. J Community Genet 2015; 6:265-73. [PMID: 25893506 DOI: 10.1007/s12687-015-0226-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/08/2015] [Indexed: 12/14/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by a CAG repeat expansion in the ATXN2 gene. Cuba has the highest prevalence (6.57 cases/10(5) inhabitants) of SCA2 in the world. The existence of 753 affected individuals and 7173 relatives at risk prompted the development in 2001 of the first predictive testing program in the country. The medical records of over 1193 individuals, who requested the test within a 13-year period, were analyzed retrospectively. The presymptomatic and the prenatal tests had uptake rates of 43.4 and 23.9 %, respectively. Several ethical challenges resulted from this program. These include the following: (1) withdrawal due to the initial protocol's length; (2) the request to participate by 16 at-risk adolescents; (3) the decision made by ten out of 33 couples with a test-positive fetus to carry the pregnancy to term, leading to de facto predictive testing of minors; (4) the elevated frequency of the ATXN2 gene large normal alleles (≥23 to 31 repeats) in the reference population. These issues have led to major changes in the guidelines of the predictive testing protocol: (1) the protocol length was shortened; (2) the inclusion criteria were expanded to reach at-risk adolescents with an interest in prenatal diagnosis; (3) interdisciplinary follow-up was offered to families in which test-positive fetuses were not aborted; (4) prenatal testing was made available to carriers of large normal alleles with ≥27 CAG repeats. The profiles of the participants were similar to those reported for other predictive testing programs for conditions like Huntington disease and familial adenomatous polyposis. The genetic counseling practices at the community level, the ample health education provided to the at-risk population, together with multidisciplinary and specialized attention to the affected families, are lessons from the Cuban experience that can be relevant for other international teams conducting predictive testing for other late-onset neurodegenerative disorders.
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Affiliation(s)
- Tania Cruz-Mariño
- Predictive Genetics Department, Center for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba,
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Kononova SK, Sidorova OG, Fedorova SA, Platonov FA, Izhevskaya VL, Khusnutdinova EK. Bioethical issues of preventing hereditary diseases with late onset in the Sakha Republic (Yakutia). Int J Circumpolar Health 2014; 73:25062. [PMID: 25147769 PMCID: PMC4111875 DOI: 10.3402/ijch.v73.25062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Prenatal diagnosis of congenital and hereditary diseases is a priority for the development of medical technologies in Russia. However, there are not many published research results on bioethical issues of prenatal DNA testing. OBJECTIVE The main goal of the article is to describe some of the bioethical aspects of prenatal DNA diagnosis of hereditary diseases with late onset in genetic counselling practice in the Sakha Republic (Yakutia) - a far north-eastern region of Russia. METHODS The methods used in the research are genetic counselling, invasive chorionic villus biopsy procedures, molecular diagnosis, social and demographic characteristics of patients. RESULTS In 10 years, 48 (76%) pregnant women from families tainted with hereditary spinocerebellar ataxia type 1 and 15 pregnant women from families with myotonic dystrophy have applied for medical and genetic counselling in order to undergo prenatal DNA testing. The average number of applications is 7-8 per year. There are differences in prenatal genetic counselling approaches. CONCLUSION It is necessary to develop differentiated ethical approaches depending on the mode of inheritance, age of manifestation, and clinical polymorphism of hereditary disease.
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Affiliation(s)
- Sardana K. Kononova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Oksana G. Sidorova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
| | - Sardana A. Fedorova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Fedor A. Platonov
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Vera L. Izhevskaya
- Research Centre for Medical Genetics of the Russian Academy of Medical Sciences, Moscow, Russia
| | - Elza K. Khusnutdinova
- Institute for Biochemistry and Genetics, Ufa Scientific Centre of the Russian Academy of Sciences, Ufa, Russia
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Sandford E, Burmeister M. Genes and genetic testing in hereditary ataxias. Genes (Basel) 2014; 5:586-603. [PMID: 25055202 PMCID: PMC4198919 DOI: 10.3390/genes5030586] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 06/25/2014] [Accepted: 07/01/2014] [Indexed: 12/19/2022] Open
Abstract
Ataxia is a neurological cerebellar disorder characterized by loss of coordination during muscle movements affecting walking, vision, and speech. Genetic ataxias are very heterogeneous, with causative variants reported in over 50 genes, which can be inherited in classical dominant, recessive, X-linked, or mitochondrial fashion. A common mechanism of dominant ataxias is repeat expansions, where increasing lengths of repeated DNA sequences result in non-functional proteins that accumulate in the body causing disease. Greater understanding of all ataxia genes has helped identify several different pathways, such as DNA repair, ubiquitination, and ion transport, which can be used to help further identify new genes and potential treatments. Testing for the most common mutations in these genes is now clinically routine to help with prognosis and treatment decisions, but next generation sequencing will revolutionize how genetic testing will be done. Despite the large number of known ataxia causing genes, however, many individuals with ataxia are unable to obtain a genetic diagnosis, suggesting that more genes need to be discovered. Utilization of next generation sequencing technologies, expression studies, and increased knowledge of ataxia pathways will aid in the identification of new ataxia genes.
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Affiliation(s)
- Erin Sandford
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Margit Burmeister
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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