Other genetic alterations that can phenocopy CHARGE syndrome, resulting in a clinical diagnosis of CHARGE syndrome, include chromosomal aberrations [e.g., 22q11.2 deletion syndrome, involving the gene encoding T-box 1 (TBX1) [19], 3p13-p21 deletions [20], and 5q11.2 deletion syndrome [21]], teratogen exposure (e.g., retinoic acid or antithyroid drugs [22]), or maternal diabetes. Here, TBX1 is linked to CHARGE syndrome.