SALL1 and ventricular septal defect: We consider the ventricular septal defect in 1 carrier for CNS-TBS to be unrelated to his being heterozygous for the p.R1054* SALL1 mutation, as it is represents an isolated, mild defect, and such heart defects are very common in the general population; however, we cannot exclude that this ventricular septal defect represents a mild phenotype with incomplete penetrance of this late-truncating SALL1 mutation.