An Overview of Down's Syndrome

This era in the history of Down's Syndrome is a challenging and exciting time to be working with Down's syndrome patients. New approaches to stimulation of the central nervous system of Down's syndrome patients, combined with new approaches to medical care for these individuals, have dramatically changed the clinical course of one of the major forms of mental retardation (Fig. 1). The incidence of Down's syndrome varies between 1 and 412 live births (Harlap, 1974) and 1 in 11,023 live births (Stark and Mantel, 1967). Most incidence figures cluster around 1 in every 688 live births, which is the figure from one of the best epidemiologic surveys done (Collman and Stoller, 1962). It is estimated that approximately 9 percent of all retarded individuals have Down's syndrome (Johnston, Speed and Evans, 1976). Historically, the first period in the history of Down's syndrome began in 1866 and lasted for over 90 years. There is evidence in both literature and art (Zellweger et al., 1977) that Down's syndrome patients existed prior to their initial clinical description by Langdon-Down; but from a medical point of view, diagnoses started to be made and patients started to be classified after 1866. Other clinicians (Seguin 1866; Duncan, 1866) also have described patients, but the early authorities all agreed in crediting Langdon-Down with the description of what he called "mongolian idiocy" (Penrose and Smith, 1966) (Table 1). Langdon-Down was influenced by contemporary scientific thought, which was dominated by Darwin's work on evolution. He suggested that if disease could break down racial barriers it could also demonstrate the unity of the human species. Thus, he named the patients "mongol" because he confused the epicanthic eye fold with the Oriental fold. The ethnic theory never became popular, but the term