ANTICIPATION AND IMPRINTING IN SPANISH FAMILIES WITH SCHIZOPHRENIA

Evidence of imprinting and anticipation, two genetic phenomena that ar e correlated with clinical sequelae, was assessed in familial schizoph renia. A sample of patients (n=291) who fulfilled the ICD-9 criteria f or schizophrenia and corresponding to the familial-type and sporadic-t ype of the disorder was recruited. Clinical anticipation and imprintin g variables such as age at onset (AAO), schizophrenia subtype, course of disease and onset type were assessed over parental (G1) and filial( G2) generations in both schizophrenia types. Anticipation assessment i ndicated significant differences in mean AAO between parent-offspring pairs in unilineal families. These differences were not explained by a cohort effect. Imprinting assessment indicated nonsignificant differe nces in AAO between the offspring of affected mothers and the offsprin g of affected fathers. The results obtained for other clinical variabl es were non-conclusive. The results suggest that anticipation, but not imprinting, is operative in schizophrenia.