Chromosome 18 translocation (18;21) (p11.1;p11.1) associated with psychosis in one family.

In the course of recruiting families with 2 schizophrenic siblings for genome screening and linkage studies, a family was found with mental retardation, schizophrenia, and/or other related psychotic illnesses in individuals who also had an unbalanced or balanced translocation between chromosomes 21-18 [t(18;21)(p11.1;p11.1)]. The pericentric region of chromosome 18 has already been noted as a possible location of a gene for bipolar psychosis. The family described here provides further evidence that this region should be examined for a candidate psychosis gene.