Most people have 23 pairs of chromosomes; one set from the mother and one from the father. However, nondisjunction errors during meiosis can lead to a case of trisomy, where there are three rather than two chromosomes. Although such events are not uncommon, they are usually lethal, and account for a high proportion of spontaneous abortions. There…

The 22q11.2 microdeletion syndrome is a genetic disorder in children with many concomitant medical and developmental problems. Communication disorders are among the most common features of this syndrome and include articulation, language, resonance, and voice problems. Awareness of these features and a multidisciplinary approach are necessary for…

This article considers the complications met by behavioral and biological studies of dyslexia by the condition's phenotypic heterogeneity and lack of uniformly applied diagnostic criteria. It notes the increasingly powerful genetic technologies and statistical methodologies used to identify genomic locations for genes involved in this complex…

A reaction to Sowell's book raises issues about behaviorally based diagnoses, stressing that developmental disorders are behaviorally defined dimensions along a continuum with no crisp partition between normalcy and disorders. It sees developmental disorders as usually the expression of extremely complex, multigenic influences on brain…

Research prospects and priorities in autism are discussed with respect to: (1) diagnosis, classification, and epidemiology; (2) clinical research; (3) neuropsychological research; (4) genetics; (5) structural and functional brain imaging; (6) postmortem studies; (7) other biological research; and (8) treatment research. Application of research…

Research in the field of developmental disabilities has found direct links between severity of a personality trait or psychopathology and particular pathology of the deoxyribonucleic acid (DNA). From studies of behavior phenotypes, new psychiatric disorders are being recognized, such as Williams syndrome. The formulation of valid behavior…

High-risk studies are undertaken for at least four reasons: (1) to derive predictors of who will develop the condition being studied that will allow earlier intervention and prevention; (2) to understand the breadth of risk (i.e., if there are other related symptoms, conditions, and impairment related to the condition being studied); (3) to…

Prenatal diagnostic procedures that can determine the existence of genetic diseases or chromosome disorders such as Down's syndrome are described, and legal considerations are outlined. Arguments for and against aborting fetuses with Down's syndrome are presented, and the need for genetic counseling for prospective parents is emphasized.…

This book is a compendium of papers presented March 18-20, 1996, at the eighteenth annual Spectrum of Developmental Disabilities course. Research findings are presented that address identification, diagnosis, management, and prognosis of specific reading disability. Individual chapters include: (1) "Dyslexia: The Evolution of a Concept" (John…

This book offers a comprehensive look at the world of adults with dyslexia based on their personal experiences and perspectives. Aimed at teachers, employers, career advisers, counselors, and others who work with, support, or live with dyslexic adults, the book uses case studies and adult "voices" to illuminate issues affecting adults with…