We investigated the expression levels of miR-137 and three candidate target genes (ZNF804A, CACNA1C, TCF4) in the DLPFC of postmortem brain tissue from 2 independent cohorts: (1) 26 subjects (10 control (CTR), 7 schizophrenia (SZ), 9 bipolar disorder (BD)) collected at the UCI brain bank; and (2) 99 subjects (33 CTR, 35 SZ, 31 BD) obtained from the Stanley Medical Research Institute (SMRI).
Our data do not support the hypothesis that variation at the polymorphic CAG/CTG repeat loci ERDA-1, SEF2-1b, MAB21L or KCNN3 influence susceptibility to BPAD in our sample.
Transmission of bipolar disorder may be characterized by anticipation and parent-of-origin effect, and extended CTG repeat at SEF2-1B gene was identified from a bipolar patient.
At present no strong evidence exists that large repeat alleles at either SEF2-1B or ERDA1 are involved in the etiology of schizophrenia or bipolar disorder.