Schizophrenia and organic brain syndrome with trisomy 8 (group-C trisomy 8 [47, XX, 8+]).

A supernumerary autosomal syndrome in the C group of submetacentric autosomes has not yet been delineated phenotypically, although cases of an extra C-group autosome have been reported. Recent technical advances (fluorescence and Giemsa banding) now permit positive identification of each autosome. The present case reports the presence of schizophrenia and organic brain syndrome in association with trisomy 8. It is the sixth case of trisomy 8 reported to date. A stress-diathesis model is used to explain the development of the psychiatric disturbances. The patient's autosomal aberration is regarded as diathetic, and the multiple congenital anomalies, surgical interventions, infections, familial, and other environmental responses as stress. This report provides further data for the phenotypic delineation of a trisomy 8 syndrome.