Report of the Chromosome 5 Workshop of the Sixth World Congress on Psychiatric Genetics.

The Chromosome 5 Workshop heard new data on a schizophrenia susceptibility locus in the 5q23.3-q31.1 region. Sixty-two pedigrees from Finland gave a lod score of 1.36 at the CSF1R locus approximately 14 cM distal to IL9/D5S393, where positive results from three pedigree collections converged at the 1997 workshop. Though positive at CSF1R, the new data were only weakly positive at the IL9 (lod 0.46) and D5S393 (lod 0.07) loci themselves. The workshop also reviewed new evidence in the 5p14.1-p13.1 region, where a large pedigree of schizophrenia of Puerto Rican extraction has suggested a susceptibility locus with a maximum lod score at D5S111. Twenty-one new pedigrees multiplex for schizophrenia in African Americans gave positive lod scores at D5S111 and flanking loci. In bipolar illness five genetically related pedigrees from the Saguenay-Lac-St. Jean region of Quebec identified a region of interest at 5q31.3-q35.1. This region overlaps with the D5S423 locus and includes the D5S812 locus and the 5q34 region, all of which are consistent with linkage in at least one other study.