Van der Woude syndrome
Van der Woude syndrome (VWS) is a condition affecting the lips, palate, and teeth. Depressions or pits typically are present on the lower lip at birth and cleft lip and/or cleft palate may also be present. Less commonly, certain teeth may not develop. VWS has previously been known as the lip pit syndrome.
Van der Woude syndrome primarily involves pits developing on the lower lip, clefting of the lip and/or palate, and the absence of certain teeth. More than 80% or more than 8 out of 10 individuals with VWS will develop pits near the center of the lower lip and about 60–70% (6 to 7 people out of 10) will have a cleft lip and/or palate at birth. About half to two-thirds of the individuals will have both lower lip pits and a cleft of the lip and/or palate. In some cases, a cleft palate is present but is not immediately noticeable; this is called a submucosal cleft palate. The least common feature in VWS, missing teeth, is seen in about 10–20% (1 to 2 people out of 10) of individuals with VWS. The teeth most commonly affected are the second incisors and the second molars.
Van der Woude syndrome is related to another condition called popliteal pterygium syndrome (PPS). Popliteal pterygium syndrome is similar to VWS in that both conditions cause lip pits and cleft lip and/or palate to develop. Popliteal pterygium syndrome differs from VWS in that popliteal pterygium webs are present at birth. Pterygium means webbed skin. Popliteal refers to the back of the legs. Popliteal pterygium means that there is webbed skin on the back of the legs, usually on the back of the knees. Individuals with PPS may also have underdevelopment of the genitals, webbing between the fingers, adhesion of the lower and upper eyelids, and fibrous bands attaching the lower and upper jaws.
Some families have features consistent with both VWS and PPS. In other words, within a family, some family members have features that are entirely consistent with VWS and other family members have features consistent with PPS. Since the gene(s) causing VWS and PPS have not been identified, it is not known why these families have features of both diseases.
Van der Woude syndrome follows autosomal dominant inheritance, indicating that every individual affected by VWS has a 50% (1 in 2) chance of passing on the condition to each of his or her children. Every individual inheriting the VWS gene will develop at least one feature of VWS. However, family members may develop different features, and some may develop very minor features whereas another family member may have more severe problems. In some cases, a family member's features may be so mild that he or she is initially thought to be unaffected. Apparently unaffected parents of a newborn with VWS should undergo a thorough examination since it is possible that one of the parents is very mildly affected. If such a parent is determined to be affected, all of his or her children will have a 50% chance of inheriting VWS.
As of 2001, the gene(s) involved in VWS have not been identified, although a specific region of chromosome 1 appears to be important in causing VWS. Research suggests that there may be at least one other gene, located on another chromosome, that may be important with regards to whether a cleft lip and/or palate develops. There is also evidence that VWS and PPS may be due to changes or mutations in the same gene or in neighboring genes on chromosome 1.
Van der Woude syndrome is a rare condition. Estimates of its incidence range from one in every 35,000 to one in every 200,000 live births. Males and females are affected equally.
Signs and symptoms
The primary symptom associated with VWS is the development of pits near the center of the lower lip (present in more than 80% of cases). In addition, 60–70% of individuals with VWS also have cleft lip and/or cleft palate. A few individuals (about 10–20%) with VWS are missing teeth, most commonly the second incisors and the second molars.
As of 2001, diagnosis of VWS relies solely upon physical examination and whether or not the characteristic features of VWS are present or absent. The family history may also have an important role in determining the diagnosis. For example, if lower lip pits and a cleft palate are present in a newborn and no popliteal webs or other feature of PPS is present, then the child has VWS. If a newborn is born with a cleft palate only but has a family history of VWS, then the child most likely has inherited VWS.
As cleft lip and/or palate occurs in other genetic conditions as well as by itself, a newborn with this birth defect needs to be fully evaluated to ensure that the reason for the cleft is correctly determined. Likewise, lower lip pits may be seen in VWS, in PPS and rarely, in a third genetic condition called orofaciodigital syndrome, type 1; consequently, a baby born with lower lips pits needs to be fully evaluated.
Prenatal diagnosis for VWS can be attempted through ultrasound examination of unborn babies at risk for the condition. Cleft lip and very rarely cleft palate can be identified on ultrasound examination. However, as some clefts are small and some individuals with VWS do not have clefts at all, a normal ultrasound examination cannot completely rule out the chance the baby has inherited VWS. An ultrasound examination with high resolution, or a level 2 ultrasound, and an experienced technician may increase the chance of seeing cleft lips or palate. Lip pits cannot be seen on ultrasound examination, even with a higher resolution ultrasound. As of 2001, genetic testing of the unborn baby is not available as the gene(s) causing VWS have not been identified.
Treatment and management
An individual with VWS will be treated and followed according to the features he or she has developed. The lip pits seen in VWS rarely cause problems. Occasionally, saliva may ooze from the pits and if so, a fistula may have developed. A fistula is an abnormal passageway or opening that develops, and in VWS, a fistula may develop between a salivary gland located under the lip and the lip surface. The pits and fistulas may be surgically removed.
If a cleft lip and/or palate is present, surgery will be necessary to correct this problem. The treatment and management of cleft lips and palates in individuals with VWS is no different from cleft lips and palates occurring in other genetic conditions or by themselves. The child will need to be followed closely for ear and sinus infections and hearing problems. The child may need speech therapy and should be followed by a dentist and orthodontist. Counseling may be needed as the child grows up to address any concerns about speech and/or appearance.
Overall, individuals with VWS do well. If a cleft lip and/or palate is present at birth, there may be some feeding difficulties in the newborn period and in the following 3 to 6 months, until the cleft is corrected. However, once surgery repairing the cleft is completed, the child typically does well. Van der Woude syndrome is not associated with a shorter lifespan.
Nagore, Eduardo, et al. "Congenital Lower Lip Pits (Van der Woude Syndrome): Presentation of 10 Cases." Pediatric Dermatology 15, no. 6 (November/December 1998): 443–445.
Rivkin, C.J., et al. "Dental Care for the Patient with a Cleft Lip and Palate. Part 1: From Birth to the Mixed Dentition Stage." British Dental Journal 188, no. 2 (January 22, 2000): 78–83.
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