The choice not to undergo genetic testing for Huntington disease: Results from the PHAROS study

• Published in: Clinical genetics Vol. 96; no. 1; pp. 28 - 34
• Main Authors: Anderson, Karen E., Eberly, Shirley, Marder, Karen S., Oakes, David, Kayson, Elise, Young, Anne, Shoulson, Ira
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2019
• Subjects: at risk; Clinical trials; Deoxyribonucleic acid; DNA; Genetic screening; genetic testing; Huntingtin; Huntington disease; Huntington's disease; genetic testing; at risk; Huntington disease
• ISSN: 0009-9163; 1399-0004; 1399-0004
• DOI: 10.1111/cge.13529

Rates of genetic testing in Huntington disease (HD) are lower than was predicted before direct DNA testing became available. Clinicians often do not have in‐depth conversations with people at risk who chose not to test. We queried 733 research subjects who chose not to learn their HD gene status when enrolling in the Prospective Huntington At‐Risk Observational Study, carried out between 1999 and 2008. Lack of an effective cure or treatment (66% of subjects) and inability to undo knowledge (66%) were the major reasons cited for choosing not to undergo HD DNA testing. Most subjects were not concerned about the length or burden of the testing process (61% and 59%, respectively). Subjects were optimistic that a treatment to improve symptoms or postpone onset would be developed within the next 10 years (56% and 53%, respectively), but they had less certainty about the prospects to prevent HD onset (36%). This is the first large, systematic study of why people at risk for HD choose not to undergo genetic testing. Attitudes about how people at risk for HD approach this life‐altering choice should be reassessed as new treatments develop, and as clinical trials now require genetic testing at entry. This study addressed the question of why people who know they are at risk for Huntington disease (HD) decide not to undergo genetic testing. The figure shows, out of a research cohort that had chosen previously not to be tested, only a small number of subjects chose to be tested during the study. Lack of an effective cure or treatment (66% of subjects) and inability to undo knowledge (66%) were the major reasons cited for choosing not to undergo HD mutation expansion testing.