These data do not support the correlation between expanded RED products (RED fragments >120) and expanded alleles at ERDA1 in trans-generational pairs with BPAD.
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.
A longer CAG repeat alleles of KCNN3 or CTG 18.1 may not be a risk factor for BPAD in Korean population and the copy number of ligation product in RED in the patients with BPAD is influenced by the longer allele of CAG/CTG of ERDA1 or CTG 18.1.
We observed no increase in frequency of larger alleles (>37 repeats) in affected individuals at SEF2-1B (BPAD: P=0.95, n= 100; SCZ: P=0.61, n=97) or at ERDA1 (BPAD: P= 0.4, n = 101; SCZ: P= 0.05, n = 151, with larger alleles more frequent in controls).