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

FMR1 Gene Variation

FMR1 gene can be found on the long arm of the X chromosome at position 27.3

Female Premutation

•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males

Female Premutation

•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males

Female Premutation

•Prevalence of premutation: •1 in 113-259 females •1 in 260-813 males

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

How do female fragile X premutation carriers perform in visual tasks involving spatial information (visuospatial processing)?

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)

Magnitude Comparison

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

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

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

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

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

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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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

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.