Although caution is warranted given the limited cohort size of our study, variants in FOXP4 seem to be associated with certain phenotypic features (e.g., vertebral abnormalities and congenital diaphragmatic hernia) that appear distinct from those observed in individuals carrying variants in FOXP1 or FOXP2. Congenital anomalies are not a common finding in individuals with pathogenic FOXP2 variants,39 and in FOXP1-associated disorder different abnormalities are recurrently reported, such as congenital heart defects or kidney abnormalities40,41 (Table S3). Here, FOXP4 is linked to congenital diaphragmatic hernia.