Van Der Woude Syndrome Health Article

Definition

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.

Description

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 eight out of 10 individuals with VWS will develop pits near the center of the lower lip and about 60–70% (six to seven 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% (one to two 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.

Genetic profile

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/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.

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.

Demographics

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.