Purpose: To describe communication profiles in children with velocardiofacial syndrome (VCFS) compared with children with Down syndrome. Methods: Four children with VCFS and four children with Down syndrome underwent cognitive and speech and language assessment. Results: Communication profiles of children with Down syndrome showed a flat profile, indicating all measures were similar and delayed relative to chronological age. Children with VCFS showed vocabulary, pattern of sound types, and Mean Babbling Length below cognitive and other language ages. Conclusion: Communication profiles of children with VCFS differed qualitatively and quantitatively from children with Down syndrome and support the hypothesis that some children with VCFS present with a profile of communication impairment that may be distinctive to the syndrome.

Indiana University-Purdue University Indianapolis (IUPUI) / The mongoloid face and craniofacial skeleton has been characterized by many investigators using clinical impressions and soft tissue measurements on living and autopsy material. Few studies have included data derived from cephalometric radiographs. The present study was designed to describe the mongoloid face and cranial base and to analyze the data. Twenty mongoloid children ranging in age from three years to 12 years, and their siblings were selected for study. A control group of children were selected on the basis of their essentially normal occlusion and facial skeleton. The data obtained from the cephalometric radiographs were analyzed in three ways. Each of the three groups of children, normal, mongoloid and their siblings were divided into four age groups, approximately three, five, seven and 11 years of age and means for the individual measurements were calculated. The sibling measurements were "corrected” to the age of the mongoloid child using the growth progression data from the normal children. The mean measurements of the “corrected” siblings and mongoloids were then compared using “t” tests for statistical significance. All children were then divided into three comparison pairs, normal-sibling, normal-mongoloid, and mongoloid-sibling, and the cephalometric measurements subjected to a multivariate, step-wise regression analysis. The growth of the maxillae and mandible were retarded in the Mongoloid children. The maxilla and mandible were positioned anteriorly under the cranial base.

Indiana University-Purdue University Indianapolis (IUPUI) / The relationship between gene copy number and protein expression levels has not thoroughly been examined in humans or mouse models of Down syndrome (DS) in relationship to developmental changes in the trisomic brain. Found on human chromosome 21 (Hsa21) and triplicated in DS, Dual-specificity tyrosine-phosphorylated regulated kinase 1A (DYRK1A) has been linked in DS to neurological deficits by restricting cell growth and proliferation. Little information exists regarding DYRK1A during perinatal development and how its expression may lead to cognitive deficits, and none exists that explores the gene-to-protein relationship during these critical time periods. This study aims to 1) Quantify variable DYRK1A expression across development as a function of age, sex, and brain region in trisomic Ts65Dn mice compared to euploid counterparts and 2) establish that the spatiotemporal pattern of developmental DYRK1A in the brain is not influenced solely by gene copy number, and that reduction of Dyrk1a in euploid and trisomic mice does not result in a corresponding global reduction of DYRK1A expression. DYRK1A was quantified in three areas of the postnatal brain at seven ages using the Ts65Dn mouse, the most studied model of DS, and found that trisomic expression is significantly increased on postnatal day ([P]6), declining by the third week to near euploid levels. We also uncovered a sexual dimorphic expression of DYRK1A when comparing animals of different sexes within the same genotype. Data from Dyrk1a knockdown mice indicated that reducing only Dyrk1a in euploid and in otherwise trisomic animals yields highly variable levels of DYRK1A, dependent on sex and tissue type, supporting the non-intuitive relationship between gene dosage and protein expression. These data emphasize the need to understand the age-dependent regulation of antecedent conditions that are causing changes in Dyrk1a expression in the brain.

The purpose of this study was to examine whether cut-points developed for the general population provide different estimates of physical activity (PA) levels in adults with Down syndrome (DS) compared to cut-points developed specifically in adults with DS. This study also attempted to objectively measure the PA levels of adults with DS and to determine if they meet the recommended amount of PA to obtain health benefits. Thirteen adults with DS wore an accelerometer to determine time spent in moderate, vigorous, and moderate-to-vigorous PA. Results indicated that different sets of cut-points responded differently in classifying moderate and vigorous PA levels, as well as in classifying whether participants met the recommended amount of PA for health benefits, as evidenced by the different estimates of moderate-to-vigorous PA in 10 minute bouts. Results also indicated that population specific cut-points should be used for assessment of PA levels in persons with DS.

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Previous research has indicated found that individuals with Down syndrome (DS) have difficulties in processing auditory information for the planning of movements relative to their peers with undifferentiated developmental handicaps. This modality-specific information-processing difficulty has been found for the preprogramming of goal-directed aiming movements (Le Clair & Elliott, 1995) and in simple reaction times (Davis, Sparrow, & Ward, 1991; Hermelin, 1964). The purpose of the present study was to assess whether or not a model of atypical cerebral specialization for the perception of speech sounds, proposed by Elliott and colleagues, could explain these findings. Thus, participants performed a choice reaction aiming task under three conditions. Colour-coded targets were cued by a visual cue at the target location, a visual cue remote from the target location, or a verbal cue identifying the target. Results revealed that while the reaction times did nCit differ between the two groups with handicaps, the participants with DS, unlike the two control groups, had significantly longer movement times in the verbal than in two visual conditions. These results support the model of biological dissociation. / Thesis / Master of Science (MS)