Association study of a functional catechol-O-methyltransferase genetic polymorphism with age of onset, cognitive function, symptomatology and prognosis in chronic schizophrenia.

The gene coding for catechol-O-methyltransferase (COMT), which is involved in the metabolism of catecholamines, has long been implicated as a candidate gene for schizophrenia. This study aimed to assess the relationship between a functional polymorphism (Val158Met) of the COMT gene and age of onset (AOO), symptomatology, global cognitive function and prognosis in patients with schizophrenia. The study enrolled 154 patients with schizophrenia from chronic wards. Results failed to show a significant association between the Val158Met polymorphism and the Brief Psychiatric Rating Scale scores, Mini-Mental State Examination scores, and Social and Occupational Functioning Assessment Scale scores, but COMT Val158Met heterozygotes had a later AOO than homozygous patients. However, by further expanding the number of patients to 228 patients, the differences in AOO among the three COMT genotypic groups was not significant. The COMT Val158Met polymorphism did not appear to significantly affect susceptibility, symptomatology, global cognitive function and prognosis in Chinese patients with schizophrenia, but the possible association with AOO merits further investigation. Copyright 2004 S. Karger AG, Basel