In low-frequency / rare variant analyses, we discovered the correlations between ADHD and collapsing effects of rare damaging variants in TEP1, MTMR10, DBH, TBCC, and ANO1. Based on biological and functional profiles of the potential risk genes and gene sets, both common and low-frequency / rare variant analyses demonstrated that ADHD genetic risk was associated with immune processes. Here, TBCC is linked to attention deficit-hyperactivity disorder.