CTNND2 and Intellectual disability: Delta-catenin’s lowered or aberrant expression resulting from copy number variations (CNVs), delta-catenin microdeletions, and a breakpoint of intron 9 on chromosome 5 of delta-catenin have all been seen in patients with intellectual disability and dyslexia (Belcaro et al., 2015; Hofmeister et al., 2015).