FOXP2 and autism spectrum disorder: More recently, an exome-sequencing study of sporadic autism spectrum disorders identified a potentially deleterious missense mutation in CNTNAP2 in a proband who also had a de novo mutation in FOXP1 (forkhead box P1).50 This is interesting as both of these genes relate to FOXP2: CNTNAP2 is regulated by FOXP2, and FOXP1 interacts with it.