Uptake of presymptomatic predictive testing for Huntington's disease

Area of Science:

• Neurogenetics
• Genetic counseling

Background:

• Huntington's disease (HD) is a progressive neurodegenerative disorder.
• Predictive genetic testing offers individuals at risk the option to learn their HD gene status.
• Understanding uptake and withdrawal factors is crucial for genetic counseling services.

Purpose of the Study:

• To evaluate the acceptance rates of predictive genetic testing for Huntington's disease.
• To identify factors influencing the decision to undergo or withdraw from predictive testing.
• To assess the demand for fetal exclusion testing in at-risk families.

Main Methods:

• Offered predictive genetic testing to 110 at-risk adults.
• Recruited an additional 91 individuals who spontaneously sought testing.
• Analyzed acceptance and withdrawal rates, and reasons for fetal exclusion testing requests.

Main Results:

• Acceptance rates varied significantly: 85.1% for external referrals versus 15.5% for invited individuals.
• A substantial number expressed interest but later withdrew from predictive testing.
• Fetal exclusion testing was infrequently requested, primarily by those unable to pursue predictive testing.

Conclusions:

• Proactive outreach for Huntington's disease predictive testing yields lower acceptance than spontaneous requests.
• Genetic counseling must address the high rate of interest followed by withdrawal in predictive testing decisions.
• Fetal testing is a limited alternative for specific genetic testing scenarios in HD families.