Survey Study Highlights Interest, Motivations Behind Modifier Gene Testing for Huntington Disease

A study led by Columbia University Irving Medical Center’s Program in Genetic Counseling explored the perspectives of individuals at risk for Huntington Disease (HD) and their interest in modifier gene testing. Overall, the results indicated that most participants surveyed would consider undergoing HD modifier gene testing, with those who have previously undergone Huntingtin (HTT) testing particularly likely to express interest in such testing.

Presented as a poster at the National Society of Genetic Counselors Annual Conference (NSGC), held November 6-10, in Seattle, Washington, the study included English-speaking adults (at least 18 years) who are at risk for developing HD but were not currently symptomatic. Respondents (n = 29) were categorized based on whether they had previously undergone HTT testing or not, and each group was further divided into “decided” and “undecided” subgroups. Participants were recruited through HD organizations and social media groups in the United States, United Kingdom, Canada and Australia using a study flyer that included a QR code.

Led by Gino Hassani, MD, a certified genetic counselor and recent graduate of Columbia University, research found that 89.5% of individuals would consider HD modifier gene testing and 69.2% of the previously tested group were likely to consider modifier gene testing. The leading motivations of the those open to both HTT testing and modifier gene testing included wanting to plan for the future (n = 17), wanting to obtain more information (n = 12), and the need to know as well as career (n = 9). Motivation for HTT testing include needing to know (n = 12), future planning (n = 9), and obtaining information (n = 8).

One patient spoke about the reasoning behind opting for gene modifier testing saying, “It would change how I live and experience every day…if I knew I had less time than I thought…I would get to live the life I deserve before it’s too late,” they added. “If I had more time than I thought, I would slow down and experience each day…HD gene modifier testing would give me power and control in a life where I have none.”

The study analyzed patients based on criteria that included a baseline informational slideshow and knowledge assessment on gene modifiers along with a 37–item Qualtrics survey including demographics and likelihood of pursuing HD modifier genes, intolerance of Uncertainty Scale (IUS) and experience of Intrusion Scale (EIS). Findings from the study suggest there is interest in modifier gene testing among the community of people at risk for HD, but the overall interest in modifier gene testing seems to be independent of HTT status.

WATCH MORE: Navigating the Patient Decision to Pursue Huntington Disease Testing: Veronica Santini, MD, MA

Although advances in genetic testing have improved clinicians’ ability to diagnose HD, the decision to pursue such testing still remains complex. During a conversation with NeurologyLive at the 2025 International Congress of Parkinson’s Disease and Movement Disorders (MDS), held October 5-9, in Honolulu, Hawaii, Veronica Santini, MD, MA, emphasized the centrality of trust and patient-centered care when navigating these decisions.

Santini, who serves as associate professor of neurology, clinical chief of the Movement Disorders Division, and chief of the Comprehensive Parkinson’s Disease Program at Yale School of Medicine, discussed that ramifications of a genetic diagnosis can be far-reaching. In the clip below, she spoke on how testing may lead to unintended consequences for presymptomatic individuals, such as potential discrimination or psychological burden—especially in the absence of disease-modifying therapy.

REFERENCE
1. Hassani G, Bergner A, Chan A, Goldman J. Exploring Perspectives of Individuals at Risk for Huntington Disease about the Utility of Modifier Gene Testing. Presented at National Society of Genetic Counselors Annual Conference: November 6-10, 2025; Seattle, WA.