NIPA2 and Oppositional defiant disorder: Both proband 15, a boy affected by TS, OCD, behavioral problems, and mild dysmorphic features, and proband 19, a girl affected by TS, mild intellectual disability, and ODD, presented the recurrent 15q11.2 deletion of about 395 Kb, which includes TUBGCP5, CYFIP1, NIPA1, and NIPA2 genes.