title: Genetic transmission and improved diagnosis of schizophrenia from pedigrees of adoptees.
abstract: In previous investigations of the prevalence of schizophrenic illness among the biological relatives of schizophrenic adoptees in Copenhagen and the remainder of Denmark, the operation of heritable spectrum illness was clearly implicated. The findings supporting that conclusion are briefly summarized. Classical chronic schizophrenia was found almost exclusively in the biological relatives of chronic schizophrenic probands and its prevalence was ten times greater than that in the biological relatives of controls. These were global diagnoses, made without knowledge of the relationships and family histories of the subjects, and based upon the descriptions of dementia praecox or schizophrenia by Kraepelin and Bleuler. They showed considerably greater sensitivity and at least equal specificity in comparison with diagnoses made on the same material in accordance with operational criteria as exemplified by DSM-III. The prevalence of a disorder in the biological relatives of adoptees with that disorder in comparison with biological relatives of control adoptees offers a useful test for the expression of genetic factors in the disorder, but also a much needed evaluation of the validity of diagnoses based on clinical observation.
authors: Intramural Research Program, NIMH, Bethesda, MD 20892.
authors: S S
authors: SS
authors: Kety
authors: L J
authors: LJ
authors: Ingraham
mesh_terms: D000300:Adoption / Q000523:psychology; D002908:Chronic Disease; D003718:Denmark; D006801:Humans; D008957:Models, Genetic; D010375:Pedigree; D010553:Personality Development; D010641:Phenotype; D012557:Schizoid Personality Disorder / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D012931:Social Environment