Includes bibliographical references and index.

Etiology, diagnosis, and development in Down syndrome / David Patterson and Ira Lott -- Etiology, diagnosis, and development in fragile X syndrome / Randi J. Hagerman -- Communication and language development in infants and toddlers with Down syndrome or fragile X syndrome / Audra Sterling and Steven F. Warren -- Language of preschool and school-age children with Down syndrome and fragile X syndrome / Joanne E. Roberts ... [et al.] -- Language profiles of adolescents and young adults with Down syndrome and fragile X syndrome / Andrea McDuffie, Robin S. Chapman, and Leonard Abbeduto -- Phonological characteristics of children with Down syndrome or fragile X syndrome / Joanne E. Roberts, Carol Stoel-Gammon, and Elizabeth F. Barnes -- Prelinguistic and early language interventions for children with Down syndrome or fragile X syndrome / Nancy C. Brady, Shelley L. Bredin-Oja, and Steven F. Warren -- Language intervention to encourage complex language use : a clinical perspective / Libby Kumin -- Increasing speech intelligibility in Down syndrome and fragile X syndrome / Johanna R. Price and Ray D. Kent -- Increasing literacy learning for individuals with Down syndrome and fragile X syndrome / Sue Buckley and Mina C. Johnson-Glenberg -- Augmentative and alternative communication for children with Down syndrome or fragile X syndrome / Nancy C. Brady -- Family well-being in Down syndrome and fragile X syndrome / Anna J. Esbensen, Marsha Mailick Seltzer, and Leonard Abbeduto.