Analysis of the DRPLA triplet repeat in brain tissue and leukocytes from schizophrenics

An expansion of the CAG triplet in the human gene called atrophin-1 or CTG-B37 causes the neuropsychiatric disease known as dentatorubral-pallidoluysian atrophy (DRPLA). We have examined the genomic DNA from brains and peripheral blood leukocytes (PBLs) of schizophrenic and non-schizophrenic individuals and PBLs from a cohort of monozygotic twins discordant or concordant for schizophrenia, for expansions of the CTG-B37 region. All samples, including non-schizophrenic/normal controls, had 7–22 CAG repeats in this region. Thus we found no evidence for an expansion of the DRPLA triplet repeat associated with schizophrenia when compared to controls. Our data suggest that an expansion in the CTG-B37 gene is not linked to or responsible for the disease schizophrenia.