Genome scan for autosomal genes conferring risk to schizophrenia in a German/ Israeli sample

The German/Israeli sample consists of 72 families (470 individuals) ascertained through a schizophrenic or chronic schizoaffective (RDC) index patient, each family having at least 2 affected siblings and parental information (67 families with both parents, 5 families with one parent, but additional nonaffected siblings). Thirteen families were from Israel (mainly non-Ashkenazi), 59 families were from Germany. The sample comprises a total of 87 (n-1) and 107 (n(n-1)1/2) sib-pair combinations for affected sib-pair analysis, identity by descent. Using fluorescence-based technology (ABI 377 Sequencer) for fragment analysis, microsatellite markers in an average distance of 10-20 cM were used for first analysis. Regions of interest, i.e., region for which a priori evidence for susceptibility genes exists, were analyzed with additional mark-ers in a distance of 2 cM and less. To date (May 1, 1998), we have completely finished the scan for chromosomes 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 13, 14, 15, 18, 19, 20, 21, and 22. The completion of the scan is anticipated for October 1998. Genome-wide significance level will be calculated. Evidence for five potential susceptibility loci has been obtained in the sample mapping to 5q31, 6p22,23, 10p14-11, 18p11.2, 22q12,13, each locus supported by additional evidence from other groups in independent samples.