Neurodevelopmental Abnormalities in Down Syndrome: Assessing Structural and Functional Deficits.

Down syndrome (DS) is a genetic intellectual disorder caused by trisomy of chromosome 21 (Hsa21) and presents with a variety of phenotypes. The correlation between the chromosomal abnormality and the resulting symptoms is unclear, partly due to the spectrum of impairments observed. However, it has been determined that trisomy 21 contributes to neurodegeneration and impaired neurodevelopment resulting from decreased neurotransmission, neurogenesis, and synaptic plasticity.