It is also noteworthy that missense mutations in CCDC22 are associated with Ritscher-Schinzel syndrome-2 (Kolanczyk et al., 2015) an X-linked recessive syndromic form of ID associated with posterior fossa defects, cardiac malformations, and minor abnormalities of the face and distal extremities. Here, CCDC22 is linked to 3C syndrome.