Copy number variations (CNVs) at 7q11.23 cause Williams-Beuren (WBS) and 7q microduplication syndromes (7Dup), two neurodevelopmental disorders with both shared and symmetrically opposite cognitive-behavioral phenotypes. Here, we profiled the proteomes of isogenic Ngn2-driven neurons that recapitulate the three dosages of 7q11.23 (hemiduplicated, control and hemideleted).