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Impaired Visuospatial Processing in Young Adult Female Fragile X
Premutation Carriers and Emerging Trends in Children
Yingratana Bella McLennan, Ling Wong, Naomi Goodrich-Hunsaker, Danielle Harvey, Flora Tassone,
Susan Rivera, Tony J. Simon
13th International Fragile X Conference, Miami 2012 July 26, 2012
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FMR1 Gene Variation
FMR1 gene can be found on the long arm of the X chromosome at position 27.3
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Female Premutation
•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males
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Female Premutation
•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males
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Female Premutation
•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?
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Psychomotor Speed
‣ Adult female fXPCs show faster psychomotor speed compared to HCs
Female Motor Reaction Times
Female Oral Reaction Times
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Visuospatial Processing Tasks
Magnitude Comparison Enumeration Verbal
(Distance Effect Task) (Numerical Spatial Attention Task)
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Magnitude Comparison
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Magnitude Comparison Task “Which of the two blue bars is longer?”
‣ Distances between the 2 bars
vary between 1-7cm in length ‣ The greater the difference in
lengths, the easier it is to judge which bar is longer
‣ Performance accuracy goes down as the differences in lengths become smaller
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Magnitude Comparison Results
‣ Female carrier adults (20-42 years old) show significant differences in
reaction times after their enhanced psychomotor speed was accounted for but had no significant difference in error rates as compared to controls
‣ However, female carrier children (7-15 years old) show no significant differences in reaction time and error rates as compared to controls
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Magnitude Comparison: Age and CGG Effects
‣ No significant correlations were found from age in the children or adults.
‣ However, a significant correlation was found in terms of worse performance and CGG expansion in adult female carriers but not in children.
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Enumeration Verbal
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Enumeration Verbal Task“How many green items do you see in the red square?”
‣ Small items (1-3 items) are effortless
‣ The answer can be perceived at a glance without counting
‣ Subitizing effect
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Enumeration Verbal Task“How many green items do you see in the red square?”
‣ Large items (5-8) are more
difficult ‣ Each individual item is
mentally separated out and counted
‣ Counting effect
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Enumeration Verbal Results
‣ Female carrier adults (21- 42 years old) show no significant differences
in reaction times or error rates as compared to controls ‣ Female carrier children (7-15 years old) also show no significant
differences in reaction time or error rates as compared to controls
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Enumeration Verbal Age and CGG Effects
‣ No significant correlations were found from age in the children or adults. ‣ However, a significant correlation was found in terms of worse
performance and CGG expansion in adult female carriers but not in children for the counting range. The subitizing range showed no correlation.
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**
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Summary
‣ Magnitude Comparison: ‣ As a group, adult female carriers show a significant difference in
performance compared to adult female controls ‣ Results show a positive correlation indicative of poorer performance
in detecting quantitative differences at higher CGG levels ‣ Enumeration Verbal: ‣ As a group, adult female carriers showed no significant differences
in performance compare to adult female controls ‣ However, results show another positive correlation between poorer
performance on the task and increasing CGG length
‣ Conclusion: Higher CGG repeat lengths may contribute to subtle impairments in visuospatial processing even when there are no group differences
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Thank you‣ Thanks to all those that participated in our study
‣ CABIL Lab members: ‣ Naomi Goodrich-Hunsaker ‣ Ling Wong ‣ Flora Tassone ‣ Danielle Harvey
‣ Collaborators: ‣ Johnson GadElkarim ‣ Liang Zhan ‣ Olusola Ajilore ‣ Alex Leow
‣ Thanks to: ‣ Susan Rivera ‣ Paul Hagerman ‣ Randi Hagerman ‣ John Olichney ‣ The rest of the NTRI team
Funding: NIDCF UL1 DE019583, NIA RL1 AG032119, NINDS RL1
NS062412, NIDA TL1 DA024854.