Heritability and linkage analysis of personality in bipolar disorder.
A previous genome scan using variance components analysis of 758 sib pairs from families of alcoholics found evidence for linkage of harm avoidance (HA) to markers on 8p21-23, and this finding was supported in a subsequent linkage study of 384 sib pairs. Here the original dataset is analysed using a new method of linkage analysis for quantitative traits that deals with extended pedigrees. As well as supporting linkage of HA to D8S549, this method also produces an MALOD of 2.4 (P=0.002) near DBH and several positive lod scores for novelty-seeking, the largest being MALODs of 3.1 (P=0.0004) near D12S391 and 3.4 (P=0.0003) near D17S1299. There is no support for linkage of novelty-seeking or HA to the regions around DRD4 and 5HTT, respectively. Additional samples will need to be studied in order to discover which regions truly harbour genetic polymorphisms influencing personality traits.