Down Syndrome Profile Abstracts

Infants & Young Children 18 (2): 86-103 (2005)

The Emerging Down Syndrome Behavioral Phenotype in Early Childhood. Implications for Practice

Fidler, Deborah J.
Human Development & Family Studies, Colorado State University, Fort Collins

Previous studies have reported a specific behavioral phenotype, or a distinct profile of behavioral outcomes, associated with Down syndrome. Until recently, however, there has been little attention given to how this behavioral profile emerges and develops over time. It is argued here that some aspects of the Down syndrome behavioral phenotype are already emerging in infants and toddlers, including emerging relative strengths in some aspects of visual processing, receptive language and nonverbal social functioning, and relative weaknesses in gross motor skills and expressive language skills. Research on the early developmental trajectory associated with Down syndrome (and other genetic disorders) is important because it can help researchers and practitioners formulate interventions that are time-sensitive, and that prevent or offset potential future negative outcomes. This article reviews evidence for the emerging Down syndrome behavioral phenotype in infants, toddlers, and preschoolers. This is followed by a discussion of intervention approaches that specifically target this developing profile, with a focus on language, preliteracy skills, and personality motivation.
Ment Retard Dev Disabil Res Rev 6 (2): 84-95 (2000)

Behavioral phenotype of individuals with Down syndrome

Chapman RS, Hesketh LJ
Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA

Evidence is reviewed for a developmentally-emerging behavioral phenotype in individuals with Down syndrome that includes significant delay in nonverbal cognitive development accompanied by additional, specific deficits in speech, language production, and auditory short-term memory in infancy and childhood, but fewer adaptive behavior problems than individuals with other cognitive disabilities. Evidence of dementia emerges for up to half the individuals studied after age 50. Research issues affecting control group selection in establishing phenotypic characteristics are discussed, as well as the possible genetic mechanisms underlying variation in general cognitive delay, specific language impairment, and adult dementia.
Am J Ment Retard 98 (5): 580-7 (1994 Mar)

Profiles and development of adaptive behavior in children with Down syndrome

Dykens EM, Hodapp RM, Evans DW
Yale Child Study Center

The profiles and developmental trajectories of adaptive behavior were cross-sectionally examined in 80 children with Down syndrome ages 1 to 11.5 years using the Vineland Adaptive Behavior Scales. Profile findings indicated a significant weakness in communication relative to daily living and socialization skills. Within communication itself, expressive language was significantly weaker than receptive skills, especially when children's overall communicative levels were above 24 months. One to 6-year-old children showed significant age-related gains in adaptive functioning, but older subjects showed no relation between age and adaptive behavior. There was, however, increased variability within this older group, implying that not all children plateau in adaptive development during the middle childhood years. Implications for development in Down syndrome and intervention programs were discussed.
Am J Ment Retard 97 (1): 39-46 (1992 Jul)

K-ABC profiles in children with fragile X syndrome, Down syndrome, and nonspecific mental retardation

Hodapp RM, Leckman JF, Dykens EM, Sparrow SS, Zelinsky DG, Ort SI
Yale University, Department of Psychology, New Haven, CT 06520

Etiology-specific profiles of intellectual abilities were compared in three groups of males with mental retardation using the Kaufman Assessment Battery for Children (K-ABC). Subjects included 10 males with fragile X syndrome, 10 with Down syndrome, and 10 with nonspecific mental retardation who were equated on both mental and chronological age. Across all three groups, sequential processing was lower than simultaneous processing or achievement, and particular subtests (e.g., Gestalt Closure) were relative strengths. Although boys with Down syndrome showed less extreme patterns of domain strengths and weaknesses, they showed a significant strength in the Sequential Processing Hand Movements subtest. In contrast, the Hand Movements subtest was lowest of all K-ABC subtests for males with fragile X syndrome. Implications were discussed for more fine-tuned research and intervention efforts.
ASHA 32 (9): 42-4 (1990 Sep)

Down syndrome. Effects on language development

Stoel-Gammon C.
Department of Speech and Hearing Sciences, University of Washington, Seattle

The newly formed picture that emerges from these recent investigations of language in children with Down syndrome must include the following: (a) language production among children with Down syndrome lags behind expected performance based on mental age; (b) in many children with Down syndrome language production skills are not commensurate with comprehension skills; the number of subjects who exhibit this uneven profile increases with age; (c) lexical and syntactic development are asynchronous in Down syndrome with syntax lagging behind; and (d) syntactic development, as measured by MLU, is characterized by periods of relatively rapid linear growth alternating with extended plateaus. Although answering some questions, these findings raise new issues that must be addressed. However, it seems clear that the traditional "slow-but-normal" characterization of the language of children with Down syndrome is no longer tenable. Instead, we must begin to think in terms of specific properties that are unique to the development of language by children with Down syndrome.
Res Dev Disabil 8 (1): 21-37 (1987)

Cognitive and learning processes in children with Down syndrome

Pueschel SM, Gallagher PL, Zartler AS, Pezzullo JC
Department of Pediatrics, Rhode Island Hospital, Providence 02902

The primary purpose of this investigation was to study cognitive and learning processes in children with Down syndrome using a recently developed instrument, the Kaufman Assessment Battery for Children (K-ABC). The results obtained from 20 children with Down syndrome were compared with those of 20 younger brothers and sisters of children in the experimental group and 20 mental age-matched nonretarded children. As predicted both the siblings (corrected for mental age) and the nonretarded children performed significantly better on both the Sequential and the Simultaneous Processing Scales of the K-ABC. However, there was no significant difference when the results of the Sequential Processing Scale were contrasted with those of the Simultaneous Processing Scale in all three groups. When subtests that use auditory-vocal (Number Recall) and auditory-motor (Word Order) channels of communication were compared with subtests that employ visual-vocal (Gestalt Closure) and visual-motor (Hand Movement) channels of communication, children with Down syndrome performed significantly better on the latter two tests than on the former two tests. The implications of these results as they relate to designing appropriate educational strategies for children with Down syndrome are discussed.