Molecular differentiation of schizoaffective disorder from schizophrenia usingBDNFhaplotypes

Abstract

BackgroundAllelic variation in the gene encoding brain-derived neurotrophic factor (BDNF) has been associated with affective disorders, but generally not schizophrenia. Brain-derived neurotrophic factor variants may help clarify the status of schizoaffective disorder.AimsTo test the hypothesis thatBDNFhaplotypes are associated with psychiatric illness marked by a prominent affective component.MethodFrequencies of a 5-markerBDNFhaplotype were examined in 600 White participants across four diagnostic categories and healthy controls.ResultsIndividuals with schizoaffective disorder and other affective disorders were significantly more likely to carry two copies of the most commonBDNFhaplotype (containing the valine allele of the Val66Met polymorphism) compared with healthy volunteers. Moreover, when compared with people with schizophrenia, individuals with schizoaffective disorder were significantly more likely to carry two copies of the common haplotype.ConclusionsTo our knowledge, this is the first candidate gene study to demonstrate association with schizoaffective disorder but not schizophrenia. Variation in theBDNFgene may be associated with the clinical phenotype of affective dysregulation across several DSM–IV diagnostic categories.