KCNAB2 and attention deficit-hyperactivity disorder: With respect to the four target genes (LIME1, KCNAB2, CAPN9, and SPTBN2) and the five CpG sites (cg00446123, cg20513976, cg07922513, cg17096979, and cg02506324), no significant difference in the levels of the CpG sites were identified between the ADHD patients and the controls (Table 2).