FURTHER INVESTIGATION OF A CHROMOSOME-15 LOCUS IN SCHIZOPHRENIA - ANALYSIS OF AFFECTED SIBPAIRS FROM THE NIMH-GENETICS-INITIATIVE

Linkage of a neurophysiological deficit associated with schizophrenia, i.e., the failure to inhibit the auditory P50 response, was previousl y reported at chromosome 15q14, The marker with the highest pairwise l od score, D15S1360, was isolated from a yeast artificial chromosome co ntaining a candidate gene, the alpha 7-nicotinic acetylcholine recepto r gene, In the present study, this linkage was further investigated in a subset of the NIMH Genetics Initiative schizophrenia families, Thes e families have not been studied neurophysiologically, as were the fam ilies in the original report, Therefore, the DSMIII-R diagnosis of sch izophrenia was used as the affected phenotype, Twenty families fulfill ed the criteria of at least one sibpair concordant for schizophrenia, along with their two parents or another affected relative outside the nuclear family, available for genotyping. Sibpair analysis showed a si gnificant proportion of D15S1360 alleles shared identical-by-descent ( 0.58; P < 0.0024). The results further support the involvement of this chromosomal locus in the genetic transmission of schizophrenia, Am, J , Med, Genet, (Neuropsychiatr, Genet,) 81:308-312, 1998, (C) 1998 Wile y-Liss, Inc.