Dermatology Online Journal

Congenital lower lip pits: A case report
A Souissi, D El Euch, M Mokni, T Badri, and A Ben Osman Dhahri
Dermatology Online Journal 10 (2): 10

Dermatology Unit, la Rabta hospital, Tunis. amel_souissi@yahoo.fr

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Abstract

The Van der Woude syndrome is a rare autosomal-dominant condition typically comprising cleft lip or cleft palate and distinctive pits of the lower lips. The degree to which individuals carrying the gene are affected varies widely, even within families. The variable manifestations include lip pits alone, absent teeth, and isolated cleft lip and palate of varying degrees of severity. Other associated anomalies have also been described. We report a case of Van der Woud syndrome manifesting with isolated lower lip pits in an adolescent female with similarly affected family members.

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Introduction

The occurrence of lip pits is autosomal dominant trait associated with developmental defects involving the paramedial portion of the vermilion of the lip. It is one of the more frequently occurring congenital malformations of the lower lip. Gurney (1940) reports four cases of lip pits in one family; Fogh-Andersen (1943) reports eleven cases of lip pits in three family groups; and Test and Falls (1947) reports lip pits in five generations of the same family [1]. Van der Woude (1954) found, after careful study of five pedigrees, that the combination of pits of the lower lip with cleft lip and palate is based on a single dominant gene; he recognized a syndrome that has since been known as the Van der Woude syndrome (VWS) [2]. We report a case of VWS manifesting by isolated lower lip pits in an adolescent female with similarly affected immediate ancestors.

Clinical summary

A 15-year-old girl presented for evaluation of bilateral depressions on both sides of her lower lip, present since birth. The presence of identical defects in the paternal grandmother, the father, and the sister was reported by the patient and confirmed by close examination of family photos. On clinical examination, bilateral punctate depressions were located on the peak of her lower lip convexity, about one half centimeter from the median line (Fig. 1). No clefting or teeth anomalies were found on oral cavity examination. No abnormalities were noted on periauricular, or thyroid regions. The lesions were surgically removed.

Figure 1
Congenital lower lip pits.

Discussion

VWS is dominantly inherited and occurs with a prevalence of approximately 1 in 60,000 to 1 in 75,000 live births, with no sex or race predilection. Although the gene has not yet been identified, it has been localized to chromosome band 1q32-q41 [3]. A second VWS locus has been mapped to 1p34 [4], and recently Kondo identified mutations in the gene encoding interferon regulatory factor 6 causing VWS [5]. Approximately 30-50 percent of all cases arise as de novo mutations.

This syndrome typically comprises cleft lip or cleft palate and distinctive pits of the lower lips; the severity of this syndrome varies widely, even within families. About 25 percent of individuals with VWS have no findings or minimal ones, such as absent teeth or trivial indentations in the lower lips. Others have severe clefting of the lip or palate.

Lower lip pits are fairly distinctive. They are observed in 88 percent of VWS patients, and in 64 percent they are the only manifestation of the syndrome [6]. The pits are usually medial, on the vermilion portion of the lower lip. They tend to be centered on small conical elevations in infancy but are simple depressions in adults. Lip pits may have variable clinical aspects, reflecting several degrees of gene expression. There may be a single pit in the center of the lip, two pits (one on the right, one on the left), or one pit on either the right or left side. They may occur on the inner lip surface, outer lip surface, or on the margin between the inner and outer lip. They may be shallow or deep, varying from asymptomatic slight depression on the vermilion border to fistulas up to 15 mm deep that penetrate into subjacent accessory salivary glands and drain small amounts of saliva, either visible or expressible, in the lip pits.

In some cases, the lip may not have a depression at all, but instead have a small, raised area (called a microform) with a nipplelike appearance. Cleft lip or palate occurs in 21 percent of patients; hypodontia is only rarely observed [7].

Other oral manifestations are infrequently reported including syngnathia (congenital adhesion of the jaws); narrow, high-arched palate; and ankyloglossia (short glossal frenulum or tongue-tie). Extraoral manifestations are reported but rare, including limb anomalies, popliteal webs, and brain abnormalities. Accessory nipples, congenital heart defects, and Hirschsprung disease have also been reported; however, it is uncertain whether these extraoral manifestations are an associated additional anomalies or infrequently expressed aspects of VWS [1].

As the specific gene for VWS is unknown, the diagnosis is made on a clinical basis by the presence of lip pits and oral clefting. Because of the variable expression of the disorder, a first-degree relative (parent, child, sibling) of a diagnosed patient is considered to be affected if they exhibit only one of the two features—either lip pits or an oral cleft. In our case, bilateral and median congenital lower lip pits associated with a suggestive familial history were consistent with the diagnosis of VWS.

Although any lip pits should at least suggest VWS, not all children with lip pits have the syndrome. In fact, commissural pits not associated with VWS occur in about 2 percent of neonates and may be associated with periauricular sinuses. Midline pits are unusual and often sporadic, as are pits of the upper lip. It is also important to differentiate VWS syndrome from other congenital anomalies that have been associated with labial pits such as popliteal pterygium syndrome and occasionally the type-1 orofaciodigital syndrome [8].

The lip pits may require no treatment if they are mild. However, they can be surgically removed either to alleviate discomfort or for cosmetic reasons. Surgical repair of cleft lip and palate or other anomalies may be required.

The recognition of familial lip pits is critical for genetic counseling. Physical examination of relatives, close examination of family photos, or interviews of older relatives may be necessary to identify minimally affected family members. However, because of the variable expressivity of the phenotype, the potential effects on unborn children are difficult to predict, and high-resolution ultrasound and fetal echocardiography may be of some use in characterizing the severity of the phenotype.

Conclusion

A 15-year-old girl with congenital lower lip pits, a rare autosomal dominant disease, is presented. No clefting, teeth abnormalities, or other associated disorders are present, but her family history is consistent with Van der Woud syndrome.

References

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2. Van der Woude A. Fistula labii inferioris congenita and its association with cleft lip and palate. Am J Hum Genet. 1954;6:244-256.

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6. Janku P, Robinow M, Kelly T, Bralley R, Baynes A,Edgerton MT. The van der Woude syndrome in a large kindred: variability, penetrance, genetic risks. Am J Med Genet. 1980;5:117-23. PubMed

7. Calista D. Congential lower lip pits. Pediatr Dermatol. 2002 Jul-Aug;19(4):363-4. PubMed

8. Wong FK, Gustafsson B. Popliteal pterygium syndrome in a Swedish family: clinical findings and genetic analysis with the Van der Woude syndrome locus at 1q32-q41. Acta Odontol Scand. 2000; 58:85-88. PubMed

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