ABSTRACT
There have been a number of genome-wide linkage scans over the past several years with at least a modest evidence of linkage on 1q, 2 and 22q and more recently good evidence for location of genes on chromosomes 6, 12 and 13q. Linkage on chromosome 8p has also been suggested by a number of workers studying different populations.1-8 We initially collected 110 patients from 33 families for which affected individuals within a family could be as distantly related as second cousins (further details on methodology are described in the Appendix on p. 28). In the genomewide scan 950 framework microsatellite markers were employed using genotyping conditions and protocols described elsewhere.9 Of the 110 affected individuals in the 33 families, 106 were available for genotyping (102 schizophrenia patients, three diagnosed with unspecified functional psychosis and one with schizo-affective disorder). The analysis was based on a model-free, multi-point, allele-sharing approach. The scan revealed suggestive or supportive evidence for linkage on six chromosomes where the LOD score was higher than one, i.e. on chromosomes 1, 3, 6, 8, 14 and on chromosome X. The most prominent peak in this study was on chromosome 8p, which over-lapped with a previously reported locus, although it appeared that our peak was 10 to 15 cM centromeric to the results of some of the other studies. This may be explained by differences in the density and order of markers or our locus may be a distinct locus.
