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…

This article presents the author's comments on Simon and Lichten's "Defining Mental Retardation: A Matter of Life and Death." Lichten and Simon (2007) argued for the use of a Total Quotient (TQ) that combines existing IQ and adaptive functioning scores into a single index. They proposed that the TQ index will improve the accuracy of mental…

This article summarizes the literature on attention deficit disorders (both with and without hyperactivity), diagnostic criteria, the disorder's prevalence, developmental course, and proposed etiologies. A conceptual framework for designing a comprehensive assessment battery is presented with specific attention to the relationship between…

This report on the state of the science in autism contains responses to questions posed by the National Institutes of Health (NIH) and recommendations concerning diagnosis, epidemiology, pathophysiology, communication/social/emotional development, medical intervention, social and behavioral intervention, and biostatistics. General recommendations…

The severity of the silent epidemic of lead poisoning and its long range effects on young children in impairment of intellectual ability, short-term memory, concentration, and reaction time have been recognized. A 3-year strategic plan for preventing childhood lead poisoning in Illinois was developed by a planning committee working through four…

This report summarizes activities and findings of a federally funded center at the Arkansas Children's Hospital which reviewed and disseminated literature on the identification and assessment of children with attention deficit disorders (ADD). Meetings throughout Arkansas led to the identification of interest areas, and findings are summarized for…