VARIANTS IN NEUROTROPHIC FACTOR GENES AND SCHIZOPHRENIC PSYCHOSES - NO ASSOCIATIONS IN A SPANISH POPULATION

Possible associations between schizophrenic psychoses, a ciliary neuro trophic factor (CNTF) null mutation and a neurotrophin in 3 (NT3) bi-a llele polymorphism were investigated in a Spanish population. The samp le consisted of 107 patients suffering from schizophrenic psychoses an d 100 healthy volunteers. There was no statistical difference in the f requencies of the mutant CNTF allele in the index and control groups ( 0.125 vs. 0.121). The frequency of the rare NT3 allele (Glu) was very low and similar in both groups (0.005). Previous findings supporting t he involvement of these genetic markers in the pathogenesis of schizop hrenic psychoses were thus not confirmed. In light of neurodevelopment al hypotheses of schizophrenia, however, genes coding for neurotrophic factors remain interesting susceptibility loci in schizophrenia resea rch. Subsequent studies should not focus exclusively on genetic altera tions but also take into account secondary changes of the neurotrophic factor system at the mRNA and protein levels. Further, the current un satisfying operationalized classification of the heterogeneous syndrom e 'schizophrenia' remains a crucial problem that could be partially re solved by introducing more differentiated diagnoses defined on the bas is of neurobiological criteria. (C) 1997 Elsevier Science Ireland Ltd.