<p> Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and communication, is of unknown etiology, and has a prevalence of 1.5% in the U.S. Atypical language patterns and anatomical findings of brain asymmetry differences between neurotypical and individuals with ASD suggest involvement of brain lateralization aberrations in autism etiology. The literature suggests an increased frequency of non-right handedness (NRH) in ASD. This dissertation aimed to study the association between hand preference and ASD in a cohort of children with ASD using a large, well-designed, population-based case-control study, CHARGE (<i>CH</i>ildhood <i> A</i>utism <i>R</i>isks from <i>G</i>enetics and the <i>E</i>nvironment). </p><p> In Chapter 1, we evaluated the association between handedness and ASD in 2- to 5-year old children. Chapter 2 longitudinally evaluated handedness outcome of the children from Chapter 1 at age 7 and older. We then investigated the utility of a parent-reported handedness assessment of children at ages 2-5 years using established hand preference at age 7+ years as the gold standard. Finally, we investigated the association between the intronic variant rs7799109 on theFOXP2 gene and ASD as well as the gene’s interaction effect on the association between NRH and ASD. </p><p> Our findings indicate that children with neurodevelopmental disorders show a delayed establishment of handedness lateralization in early stages of childhood with a subset of these children still remaining NRH at age 7 years. Language deficits in children at ages 2 to 5 years are associated with NRH and ASD, and is a determinant of NRH in ASD at age 7 years and older. Our study also supports current literature that hand preference may have genomic underpinnings in ASD.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10252664 |
| Date | 08 June 2017 |
| Creators | Tezcan, Ayse Zubeyde |
| Publisher | University of California, Davis |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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