L1CAM and acrocallosal syndrome: Interestingly, L1CAM is the only gene included in the duplicated region which has been verified to be a ENS-expressed gene and to play a key role in its development during embryogenesis [23], and some cases of patients with either X-linked hydrocephalus or acrocallosal syndrome and HSCR have been reported to present L1CAM mutations (visit HGMD http://www.hgmd.cf.ac.uk/ac/all.php).