FOLLOW-UP OF A REPORT OF A POTENTIAL LINKAGE FOR SCHIZOPHRENIA ON CHROMOSOME 22Q12-Q13.1 .2.

A collaboration involving four groups of investigators (Johns Hopkins University/Massachusetts Institute of Technology; Medical College of V irginia/The Health Research Board, Dublin; Institute of Psychiatry, Lo ndon/University of Wales, Cardiff; Centre National de la Recherche Sci entifique, Paris) was organized to confirm results suggestive of a sch izophrenia susceptibility locus on chromosome 22 identified by the JHU /MIT group after a random search of the genome. Diagnostic, laboratory , and analytical reliability exercises were conducted among the groups to ensure uniformity of procedures. Data from genotyping of 3 dinucle otide repeat polymorphisms (at the loci D22S268, IL2RB, D22S307) for a combined replication sample of 256 families, each having 2 or more af fected individuals with DNA, were analysed using a complex autosomal d ominant model. This study provided no evidence for linkage or heteroge neity for the region 22q12-q13 under this model. We conclude that if t his region confers susceptibility to schizophrenia, it must be in only a small proportion of families. Collaborative efforts to obtain large samples must continue to play an important role in the genetic search for clues to complex psychiatric disorders such as schizophrenia. (C) 1994 Wiley-Liss, Inc.