Abstract Details

Title CAG repeats within the non-pathological range in the HTT gene influence personality traits in patients with Subjective Cognitive Decline

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P11 - Poster Session 11 (11:45 AM-12:45 PM)

Poster/Presentation
Number 3-004

Background HTT is a gene containing a key region of CAG repeats. When expanded beyond 39 repeats, Huntington disease (HD) develops. Individuals with less than 35 repeats are not associated with HD. A higher number of repeats in HTT confer advantageous changes in brain structure and general intelligence. On the other hand, subjects carrying experienced more depressive symptoms compared to control subjects.

Objective We aimed to evaluate the effect of CAG repeat length on personality traits and depression in patients with subjective cognitive decline (SCD).

Design/Methods We included 54 SCD patients. All patients underwent an extensive neuropsychological battery at baseline, APOE genotyping and analysis of HTT alleles to quantify the number of CAG repeats. We used the Big Five Factors Questionnaire (BFFQ) and Hamilton Depression Rating Scale respectively (HDRS) to assess personality traits and depression at baseline. Patients who did not progress to Mild Cognitive Impairment (MCI) had at least 5-year follow-up time.

Results

In the whole sample, CAG repeat number in the shorter HTT allele was inversely correlated with conscientiousness (Pearson=-0.364, p=0.007). During the follow-up, 14 patients (25.93% [95% C.I.=14.24-37.61]) progressed to MCI (p-SCD) and 40 (74.07% [95% C.I.=62.39-85.76]) did not (np-SCD). When we performed the same analysis in the p-SCD group, we found that: CAG-repeat length on the shorter allele was inversely correlated with energy (Pearson=-0.694 p=0.006) and conscientiousness (Pearson=-0.695, p=0.006); CAG-repeat length on the longer allele was inversely correlated with conscientiousness (Pearson=-0.901, p<0.001) and directly correlated with emotional stability (Pearson=0.639, p=0.014). All the relationships still remained significant when adjusted for age, sex, APOE status, years of education and HDRS.

Conclusions We showed that CAG repeats in the HTT gene within the no-pathological range might influence personality traits. Low level of conscientiousness, low level of energy and high level of emotional stability are associated with expansion of CAG repeats only in p-SCD.

Authors/Disclosures
Salvatore Mazzeo (University of Florence) PRESENTER	Mr. Mazzeo has nothing to disclose.
	No disclosure on file
	No disclosure on file
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Sandro Sorbi	Sandro Sorbi has nothing to disclose.
Benedetta Nacmias	Benedetta Nacmias has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier.
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