Associations and Other Features of CL/P According to Phenotype

Associations and Other FeaturesCleft Phenotype
Cleft Lip With or Without Cleft Palate (∼1 in 600–700 US Births)CP (∼1 in 1000–1500 US Births)
SexMale:female ratio 2:12Male:female ratio 1:22
Racial/ethnicMost common in American Indian, Alaska Native, Latino, and Asian subjects (1/300–1/500)3; intermediate in white subjects (1/1000); and less common in black subjects (1/2500)1No racial/ethnic association
Syndrome30% associated with a syndrome150% associated with a syndrome1
LocationCLP is about twice as common as CL ± A.4 Usually, the CL is contiguous with the cleft alveolus and CP. Less commonly, there may be a CL that is separated from the CP by apparently normal alveolar ridge and/or anterior palateCP may involve the entire secondary palate (posterior to the incisive foramen) or a more posterior portion of the palate. A submucosal cleft palate is a defect in the palatal musculature with intact overlying mucosa, and the effects on feeding, Eustachian tube function, and speech may be similar to those in children with an overt CP
Unilateral vs bilateral and sidednessApproximately 75% of clefts involving the lip are unilateral.5 Among unilateral CL ± P, those affecting the left side are twice as common as the right side5CP is usually in the midline