Cleft Palate And Lip

Definition

A cleft is a birth defect that occurs when the tissues of the lip and or palate of the fetus do not fuse very early in pregnancy. A cleft lip, sometimes referred to as a harelip, is an opening in the upper lip that can extend into the base of the nostril. A cleft palate is an opening in the roof of the mouth.

Description

Infants born with cleft lips will have an opening involving the upper lip. The length of the opening ranges from a small notch to a cleft that extends into the base of the nostril. Cleft lips may involve one or both sides of the lip.

Cleft palates are openings in the palate, which is the roof of the mouth. The size and position of the opening varies. The cleft may only be in the hard palate, the bony portion of the roof of the mouth opening into the floor of the nose, or it may only occur in the soft palate, the soft portion of the roof of the mouth. The cleft palate may involve both the hard and soft palate and may occur on both sides of the center of the palate.

Cleft lips can develop with or without cleft palates. Cleft palates may also occur without cleft lips.

Genetic profile

Cleft lip and palates not associated with a syndrome are caused by a combination of genetic and environmental factors. Inheritance caused by such a combination is called multifactorial. The embryo inherits genes that increase the risk for cleft lip and or palate. When an embryo with such genes is exposed to certain environmental factors, the embryo develops a cleft.

The risk of a baby being born with a cleft lip or palate increases with the number of affected relatives and increases with relatives that have more severe clefts.

Environmental factors that increase the risk of cleft lip and palate include cigarette and alcohol use during pregnancy. Some drugs also increase the incidence of clefting, such as phenytoin, sodium valproate, and methotrexate. The pregnant mother's nutrition may affect the incidence of clefting as well.

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Author Info: Farris F. Gulli MD, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Genetic Disorders Part I, 2002

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.