The genetics, if any, of infantile autism and childhood schizophrenia

Abstract

A critical examination of the data for and against genetic factors in early infantile autism and childhood schizophrenia is presented. The extreme rareness of both disorders made analysis difficult. No strong evidence exists implicating genetics in the development of childhood psychoses that begin before the age of 5. Family pedigree data fail to support psychogenic transmission because very few siblings of early onset cases are affected. Biological but not genetic etiological agents are more likely. Genetic factors are implicated in the development of psychoses that begin near pubescence and such factors appear to overlap with those for adult schizophrenia. Reevaluation of the minimum age of onset for adult-type schizophrenia is suggested.

Autism Research: Lessons from the Past and Prospects for the Future

“…Vertical transmission would not be expected in view of the infrequency with which individuals with autism married and had children, and the cytological techniques available at the time were too crude to have much confidence in negative findings. Looking back, I must admit that I felt pretty foolish about my wrong inferences but it is noteworthy that geneticists took even longer than I did to realize the error of their ways (see, for example, Hanson & Gottesman, 1976).…”

Infant siblings and the investigation of autism risk factors

“…They went on to note that such studies could be effective and economical for etiologic research. A 1976 review of the genetics of infantile autism and childhood schizophrenia [2] highlighted the potential of Pearson and Kley's high-risk design for etiologic research, but at that time the only such studies underway were investigations focusing on children of parents with schizophrenia (reviewed by Garmezy [3]). In the 1980s, prompted by the 1977 publication of Folstein and Rutter's seminal autism twin study [4], siblings of autism probands increasingly were included in research samples; however, these were largely cross-sectional family studies in which researchers looked at recurrence risk and genetic segregation or linkage, not at prospective investigations where at-risk siblings were the subjects of principal interest.…”

Theories of schizophrenia: a genetic-inflammatory-vascular synthesis

“…Likewise, prospective studies of children at high risk for schizophrenia report developmental anomalies in motor skills, cognition, and attention long before the onset of overt illness [17-19]. Overt psychotic symptoms for some individuals usually start in the late teenage years or early twenties, but the illness can start as early as middle childhood [20] and may, more rarely, start in old age [21] p 73].…”