SCHIZOPHRENIA SUSCEPTIBILITY ASSOCIATED WITH INTERSTITIAL DELETIONS OF CHROMOSOME 22Q11

We report the results of two studies examining the genetic overlap bet ween schizophrenia and velocardiofacial syndrome. In study A, we chara cterize two interstitial deletions identified on chromosome 22q11 in a sample of schizophrenic patients. The size of the deletions was estim ated to be between 1.5 and 2 megabases. In study B, we examine whether variations in deletion size are associated with the schizophrenic phe notype in velocardiofacial syndrome patients. Our results show that a region of the genome that has been previously implicated by genetic li nkage analysis can harbor genetic lesions that increase the susceptibi lity to schizophrenia. Our findings should facilitate identification a nd cloning of the schizophrenia susceptibility gene(s) in this region and identification of more homogeneous subgroups of patients.