Cleft palate is a birth defect that occurs when, during embryonic development, the roof of the mouth---called the palate---does not close properly. Often, the upper lip is also clefted. In most cases, a cleft palate with or without cleft lip is the only abnormal feature a child has. This is called isolated cleft palate. Sometimes, however, an underlying syndrome is the cause of the cleft palate. Most often, the syndrome is due to a genetic mutation that has occurred during the baby's development in the womb.
Deletion 22q11.2 Syndrome
One of the most common genetic syndromes, deletion 22q11.2 syndrome, has many other names: DiGeorge syndrome, velocardiofacial syndrome, and Sprintzen syndrome to name a few. People with this syndrome can have a wide range of features, including cleft lip and palate, immune deficiency, heart defects and psychiatric problems. It is caused by a deletion of several genes located in chromosome 22. Most cases occur sporadically, though some can be inherited from an affected parent.
Fetal Alcohol Syndrome
Fetal alcohol syndrome (FAS) is caused when a fetus is exposed to excessive amounts of alcohol. The exposure is more than just a few drinks early in pregnancy and FAS generally only occurs in infants of alcoholic women. The main features of FAS are central nervous system abnormalities, characteristic facial features, and growth delay. Occasionally, a child with FAS is born with a cleft lip and palate.
Stickler Syndrome
Babies with Stickler syndrome often have chins that are so small it causes the tongue to sit abnormally in the mouth. During development, the tongue blocks the ability of the palate to close properly causing a U-shaped cleft palate when the baby is born. This is called "Pierre-Robin sequence." Other features of Stickler syndrome include hearing loss, eye abnormalities, and scolosis or other skeletal problem. This syndrome is caused by genetic changes, or mutations, in the gene for type II collagen in the body. Stickler syndrome can be inherited from a parent or occur sporadically.
Van der Woude Syndrome
Individuals with Van der Woude syndrome (VWS) are often born with a cleft lip and palate and can have "pits" in the skin near the lip. Caused by a mutation in the IRF6 gene, VWS is often inherited from a parent. This syndrome can be variable in the degree of severity and can go undiagnosed in a family. Genetic testing for the IRF6 gene determines if a person has VWS.
References
- "The Lancet"; Cleft Lip and Palate; Peter A Mossey; 2009
- "Seminars in Pediatric Neurology"; Deletion 22q11: Spectrum of Associated Disorders; Beverly N. Hay; 2007
- "Obstetrics & Gynecology"; Recognition and prevention of fetal alcohol syndrome. R. Louise Floyd; 2005
- "American Journal of Medical Genetics" Stickler Syndrome: Clinical Characteristics and Diagnostic Criteria; Peter S. Rose; 2005.
- "GeneReveiws": IRF6-related syndromes.
