Investigating Neuroimaging Endophenotypes for Autism Spectrum Disorder
Condition: Autism Spectrum Disorder
MeSH terms: Autistic Disorder; Autism Spectrum Disorder; Child Development Disorders, Pervasive
Study type: Observational

Summary: 
      Specific Aims: This study aims to examine the hypothesis that individuals with Autism
      spectrum disorder (ASD) and their unaffected siblings shared alterations in gray and white
      matter volume and their associated intrinsic functional connectivity, to build upon limited
      literature about neuroimaging endophenotypes of ASD. The investigators also aim to test
      whether these shared differences are associated with behavioral autistic traits.
    

Detailed description: 
      Autism spectrum disorder (ASD) is a highly heritable neurodevelopmental disorder, yet the
      search for genes with a definitive role in its etiology has remained elusive. Deconstructing
      the disorder with endophenotypic approach should boost the statistical power of genetic
      studies and clarify the pathophysiology of autism. Neuroimaging data provides evidence for
      atypical trajectories of brain growth in ASD, which result in differences in neuroanatomy and
      connectivity in the widespread neural systems. As genetic factors are responsible for a
      significant amount of variation in neuroanatomy and intrinsic functional connectivity, shared
      alterations in brain morphology and associated functional connectivity between individuals
      with ASD and their unaffected siblings is likely a useful endophenotype. Nonetheless, such
      multi-modal approach has never been tested in study on endophenotypic markers for ASD. The
      study aims to fill in the gap.

      The investigators plan to recruit 90 participants (30 adults with ASD, 30 unaffected
      siblings, and 30 healthy controls), without current and past history of any systemic physical
      illness, neither any major psychiatric disorder other than ASD. All the participants will
      receive psychiatric interviews (the Chinese version of the Autism Diagnostic
      Interview-Revised, ADI-R; the Chinese Version of the Kiddie Epidemiologic version of the
      Schedule for Affective Disorders and Schizophrenia, K-SADS-E). They will receive the Wechsler
      Adult Intelligence Scale-3rd edition(WAIS-III) first to ensure their full-scale IQ greater
      than 70. The MRI assessments (T1 imaging, single-echo echo planar imaging(EPI) resting-state
      fMRI) will be subsequently arranged within 2 weeks after psychiatric/neuropsychological
      assessments.

      The investigators anticipate that this study (1) will be the first report in Taiwan to report
      neuroimaging endophenotypes for ASD; (2) will be the first report in the world on the shared
      structural and functional connective differences by ASD and their unaffected siblings; (3)
      will provide further evidence about the mechanism underpinning the broad autism phenotype.
    

Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        The sample consists of 30 adults with ASD, and 30 sex-matched unaffected siblings, and 30
        healthy volunteers.