Autism spectrum disorders / Sally J. Rogers, Sally Ozonoff, Robin L. Hansen -- Attention-deficit/hyperactivity disorder / Julie B. Schweitzer, Murat Pakyurek, J. Faye Dixon -- Fragile X syndrome / Mary Jacena S. Leigh, Randi J. Hagerman, David Hessl -- Chromosome 22q11.2 deletion syndrome / Kathleen Angkustsiri, Tony J. Simon -- Tourette syndrome, tic disorders, and comorbidities / Joan R. Gunther, Frank R. Sharp -- Down syndrome / Liga Bivina, Billur Moghaddam, Terry D. Wardinsky -- Angelman and Prader-Willi syndromes / Molly McGinniss, Billur Moghaddam -- Williams syndrome / Mary Beth Steinfeld, Robin L. Hansen -- Sex chromosome aneuploidy / Jeannie Visootsak, Nicole Tartaglia -- Disorders of learning, dyslexia, dysgraphia, dyscalculia, and other symbolic dysfunctions / Ingrid N. Leckliter, Janice L. Enriquez -- Speech and language disorders in childhood a neurodevelopmental perspective / Ann M. Mastergeorge.