Contributors of these 12 articles describe distinct speech and language issues associated with two common genetically caused developmental disabilities. They focus on intervention and care along the life span as they describe identification and development in Down Syndrome and Fragile X Syndrome, including their etiology, diagnosis and development, and give speech and language profiles for infants and toddlers, preschool and school-age children, adolescents and young adults, and phonological characteristics of children. They also describe interventions that address pre-linguistic and early childhood, encourage complex language use, increase speech intelligibility, increase literacy learning, improve augumentative and alternative communication, and boost family well-being. The appendix includes a list of professional organizations. Articles include comprehensive references. Annotation ©2008 Book News, Inc., Portland, OR (booknews.com)