As the individual with the heterozygous frameshift variant in our cohort had a phenotype entirely in line with the individuals with the likely pathogenic forkhead box domain missense variants: a congenital diaphragmatic hernia, short stature, developmental delays, hypotonia, and cryptorchidism, we assume that the FOXP4 variant is causative. Here, FOXP4 is linked to cryptorchidism.