CONFIRMATION OF ASSOCIATION BETWEEN EXPANDED CAG CTG REPEATS AND BOTHSCHIZOPHRENIA AND BIPOLAR DISORDER/

Recent studies have suggested that expanded CAG/CTG repeats contribute to the genetic aetiology of schizophrenia and bipolar disorder. Howev er, the nature of this contribution is uncertain and difficult to pred ict from other known trinucleotide repeat diseases that display much s impler patterns of inheritance. We have sought to replicate and extend earlier findings using Repeat Expansion Detection in an enlarged samp le of 152 patients with schizophrenia, 143 patients with bipolar disor der, and 160 controls. We have also examined DNA from the parents of 6 2 probands with schizophrenia or bipolar disorder. Our results confirm our earlier, preliminary findings of an association between expanded trinucleotide repeats and both schizophrenia and bipolar disorder. How ever, our data do not support the hypothesis that trinucleotide repeat expansion can alone explain the complex patterns of inheritance of th e functional psychoses neither can this mechanism fully explain appare nt anticipation.