CRLF1 and Cowden syndrome 1: Unlike what has been observed in other syndromes (such as DS, in which structural anomalies and atypical development cause weak lip closure, compression pattern without the use of intraoral suction, and/or dysfunction of upper esophageal sphincter when bottle/breastfed [24]), in newborns with CS/CISS1, the presence of tonic contractions of facial muscles elicited by crying or tactile or painful stimulation can seriously limit the newborn’s ability to feed orally.