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Familial incidence of labial pits
Am J Otolaryngol 7 : 3 1 1 - 3 1 3 , 1986
Familial Incidence of Labial Pits MACK L. CHENEY, M.D., WENDY R. CHENEY, B.D.Sc., AND FRANCIS E. LEJEUNE, JR., M.D.
Congenital pits of the lower lip are rare malformations, inherited in an autosomal dominant fashion (penetrance approximately 80 per cent), and closely associated with cleft lip, cleft lip/palate, or isolated cleft palate. The phenomenon of paramedian labial pits is discussed, and an example of inheritance pattern is reported.
Congenital pits of the lower lip are rare malformations first described by Demarquay in 1845.1 Lower lip pits can be generally classified as either paramedian or commissural in type. The commissural lip pit is fairly common, is usually located bilaterally at the oral commissures, and typically remains asymptomatic. On the other hand, p a r a m e d i a n lip pits are extremely rare, are almost always bilaterally located between the midline and the oral commissures, and are closely associated with facial clefting. This article will address the phenomenon of paramedian labial pits. The incidence of congenital labial pits is low. Received October 24, 1985, from the Department of Otolaryngology/Head and Neck Surgery, Ochsner Clinic and Alton Ochsner Medical Foundation, New Orleans, Louisiana. Accepted for publication February 3, 1986. Address reprint requests to Dr. LeJeune: Ochsner Clinic, 1514 Jefferson Highway, New Orleans, LA 70121. 0196-0709/86 $00.00 + .25
~
Van der Woude's report 2 in 1954 stressed four characteristics: a tendency to manifest itself in more than one member of the family; a definite hereditary influence; greater incidence in females (2:1); and an affinity for the lower lip. 3 The frequency can only be estimated, as no c o m p r e h e n s i v e survey has been carried out. However, most authors have estimated the frequency at 1:75,000 to 1:100,000. 4 The entity usually appears as two pits or humps on the vermilion portion of the lower lip, equidistant from the midline. Some are mere depressions, while others channel 10 to 15 mm deep with openings like nipples. The pits themselves usually remain asymptomatic but may on occasion produce a sparse mucinous secretion. 5 The origin of labial pits is thought to be small invaginations of the embryonal mandibular process when the embryo is 7.5 to 12.5 m m long. 6 As growth proceeds, these furrows deepen into
~
29 Persons in All Sibships
15/29 Affected Bilateral
OK
CLP Pits &
Unilateral
CLP
7 Male
Uni
Bifid Nose
F i g u r e 1. family tree.
A be~n s t
Patient's
SP
~ "c:';" ~176 Pits Onl~
Billltersl
CLP ~ Pits
OK OK
Unilate~l~
~Clse ~tudy PatientPits
Only
311
FAMILIAL INCIDENCE OF LABIAL PITS
i!!!~ji;84 ~:~
nant mode of inheritance with variable expressitivity likely. 5 In addition to the striking association with cleft lip and/or palate, congenital labial pits have been associated with numerous other malformations. These include anomalies of the extremities, genitourinary system, bifid vulva, mental retardation, and others. 5 PATIENT'S FAMILY TREE
Figure 2 (top). Preoperative view of labial pits. Figure 3 (bottom). Postoperative view of labial pits.
American Journal of
OtolaryngoJogy 312
canals that eventually incorporate into the substance of the lower lip in the normal individual. If, however, the canals persist, congenital labial pits remain. 5 Microscopic sections show an invaginated w e d g e of m u c o s a s u r f a c e d by s t r a t i f i e d squamous epithelium. The epithelium is continuous into the invaginated fistula. The lamina propria is composed of dense collagen and contains a few minor salivary glands. The specific causes of congenital labial pits are not known, although almost certainly heredity plays a major role, as it does in cleft lips and palate2 Inheritance of clefts in families with labial pits is of a different character than in families where no lip pits occur. Van der Woude 2 found that the inheritance of pits and clefts is based on a single autosomal dominant gene of variable expressivity. This means that a mildly affected individual can pass the trait on in a very severe form and vice versa. In fact, patients with simple labial pits have shown to produce a high percentage of cleft offspring. Fraser also found that labial pits can be associated with cleft lip, cleft lip/palate, or isolated cleft palate within the same family 7 and suggested the syndrome is inherited as a dominant mutant gene. Cervenka et al. 5 looked at members of 38 affected families. They, too, found a simple domi-
Figure 1 illustrates the family tree of a sevenyear-old boy who was seen in the otolaryngology clinic with characteristic labial pits. An analysis of the patient's family tree confirms the mode of inheritance to be of a simple, dominant nature. There is no sexual preference, and mildly affected individuals did pass on severe forms of the trait. For example, the patient's mother has labial pits only, but the patient's brother has a bilateral cleft of the lip and palate as well as mucous labial pits. Penetrance is the frequency with which a heritable trait is manifested by individuals carrying the principal gene or genes conditioning it. In the patient's family, penetrance is 93.4 per cent compared with 80 per cent estimated by Cervenka et al. 5 Thus, the probability of the pao tient's offspring being affected with the trait is high, since 60 to 70 per cent of offspring of individuals with labial pits have cleft lip and/or palate. TREATMENT The excision of labial pits is commonly performed for cosmetic reasons. Excision may be necessary to help with emotional problems or for the control of recurrent infection of the cysts. The surgical technique consists of gentle probing of the m u c o u s tract with excision of the tract and the surrounding glandular tissue (Figs. 2 and 3). Care should be taken to remove all glandular tissue from around the tract, as postgenerative complications most often are associated with remnants of secreting tissue. The resulting defect is then closed in layers with careful attention to reapproximating the vermilion border of the lip.
References 1. Demarquay JN: Quelques considerations sur ]e bec-delievre. Gaz Med Paris 13:52-53, 1845
CHENEY ET AL. 2. Van der Woude A: Fistual labii inferioris congenita and its association with cleft lip and palate. Am J Hum Genet 6:244-256, 1954 3. Soricelli DA, Bell L, Alexander WA: Congenital fistulas of the lower lip. Oral Surg 21:511-516, 1966 4. Stewart RE, Prescott GH (eds): Oral Facial Genetics, 1st Ed. St. Louis, C. V. Mosby Co., 1976, pp 500-662 5. Cervenka J, Gorlin RJ, Anderson VE: The syndrome of
pits of the lower lip and cleft lip and/or palate. Genetic considerations. Am J Hum Genet 19:416, 1967 6. Whitaker LA, Pashayan M, Reichman J: A proposed new classification of craniofacial anomalies. Cleft Palate J 18:161, 1981 7. Fraser FC: The genetics of cleft lip and cleft palate. Am J Hum Genet 22:36, 1970
Volume 7 Number 4 July 1986 313
Familial Incidence of Labial Pits MACK L. CHENEY, M.D., WENDY R. CHENEY, B.D.Sc., AND FRANCIS E. LEJEUNE, JR., M.D.
Congenital pits of the lower lip are rare malformations, inherited in an autosomal dominant fashion (penetrance approximately 80 per cent), and closely associated with cleft lip, cleft lip/palate, or isolated cleft palate. The phenomenon of paramedian labial pits is discussed, and an example of inheritance pattern is reported.
Congenital pits of the lower lip are rare malformations first described by Demarquay in 1845.1 Lower lip pits can be generally classified as either paramedian or commissural in type. The commissural lip pit is fairly common, is usually located bilaterally at the oral commissures, and typically remains asymptomatic. On the other hand, p a r a m e d i a n lip pits are extremely rare, are almost always bilaterally located between the midline and the oral commissures, and are closely associated with facial clefting. This article will address the phenomenon of paramedian labial pits. The incidence of congenital labial pits is low. Received October 24, 1985, from the Department of Otolaryngology/Head and Neck Surgery, Ochsner Clinic and Alton Ochsner Medical Foundation, New Orleans, Louisiana. Accepted for publication February 3, 1986. Address reprint requests to Dr. LeJeune: Ochsner Clinic, 1514 Jefferson Highway, New Orleans, LA 70121. 0196-0709/86 $00.00 + .25
~
Van der Woude's report 2 in 1954 stressed four characteristics: a tendency to manifest itself in more than one member of the family; a definite hereditary influence; greater incidence in females (2:1); and an affinity for the lower lip. 3 The frequency can only be estimated, as no c o m p r e h e n s i v e survey has been carried out. However, most authors have estimated the frequency at 1:75,000 to 1:100,000. 4 The entity usually appears as two pits or humps on the vermilion portion of the lower lip, equidistant from the midline. Some are mere depressions, while others channel 10 to 15 mm deep with openings like nipples. The pits themselves usually remain asymptomatic but may on occasion produce a sparse mucinous secretion. 5 The origin of labial pits is thought to be small invaginations of the embryonal mandibular process when the embryo is 7.5 to 12.5 m m long. 6 As growth proceeds, these furrows deepen into
~
29 Persons in All Sibships
15/29 Affected Bilateral
OK
CLP Pits &
Unilateral
CLP
7 Male
Uni
Bifid Nose
F i g u r e 1. family tree.
A be~n s t
Patient's
SP
~ "c:';" ~176 Pits Onl~
Billltersl
CLP ~ Pits
OK OK
Unilate~l~
~Clse ~tudy PatientPits
Only
311
FAMILIAL INCIDENCE OF LABIAL PITS
i!!!~ji;84 ~:~
nant mode of inheritance with variable expressitivity likely. 5 In addition to the striking association with cleft lip and/or palate, congenital labial pits have been associated with numerous other malformations. These include anomalies of the extremities, genitourinary system, bifid vulva, mental retardation, and others. 5 PATIENT'S FAMILY TREE
Figure 2 (top). Preoperative view of labial pits. Figure 3 (bottom). Postoperative view of labial pits.
American Journal of
OtolaryngoJogy 312
canals that eventually incorporate into the substance of the lower lip in the normal individual. If, however, the canals persist, congenital labial pits remain. 5 Microscopic sections show an invaginated w e d g e of m u c o s a s u r f a c e d by s t r a t i f i e d squamous epithelium. The epithelium is continuous into the invaginated fistula. The lamina propria is composed of dense collagen and contains a few minor salivary glands. The specific causes of congenital labial pits are not known, although almost certainly heredity plays a major role, as it does in cleft lips and palate2 Inheritance of clefts in families with labial pits is of a different character than in families where no lip pits occur. Van der Woude 2 found that the inheritance of pits and clefts is based on a single autosomal dominant gene of variable expressivity. This means that a mildly affected individual can pass the trait on in a very severe form and vice versa. In fact, patients with simple labial pits have shown to produce a high percentage of cleft offspring. Fraser also found that labial pits can be associated with cleft lip, cleft lip/palate, or isolated cleft palate within the same family 7 and suggested the syndrome is inherited as a dominant mutant gene. Cervenka et al. 5 looked at members of 38 affected families. They, too, found a simple domi-
Figure 1 illustrates the family tree of a sevenyear-old boy who was seen in the otolaryngology clinic with characteristic labial pits. An analysis of the patient's family tree confirms the mode of inheritance to be of a simple, dominant nature. There is no sexual preference, and mildly affected individuals did pass on severe forms of the trait. For example, the patient's mother has labial pits only, but the patient's brother has a bilateral cleft of the lip and palate as well as mucous labial pits. Penetrance is the frequency with which a heritable trait is manifested by individuals carrying the principal gene or genes conditioning it. In the patient's family, penetrance is 93.4 per cent compared with 80 per cent estimated by Cervenka et al. 5 Thus, the probability of the pao tient's offspring being affected with the trait is high, since 60 to 70 per cent of offspring of individuals with labial pits have cleft lip and/or palate. TREATMENT The excision of labial pits is commonly performed for cosmetic reasons. Excision may be necessary to help with emotional problems or for the control of recurrent infection of the cysts. The surgical technique consists of gentle probing of the m u c o u s tract with excision of the tract and the surrounding glandular tissue (Figs. 2 and 3). Care should be taken to remove all glandular tissue from around the tract, as postgenerative complications most often are associated with remnants of secreting tissue. The resulting defect is then closed in layers with careful attention to reapproximating the vermilion border of the lip.
References 1. Demarquay JN: Quelques considerations sur ]e bec-delievre. Gaz Med Paris 13:52-53, 1845
CHENEY ET AL. 2. Van der Woude A: Fistual labii inferioris congenita and its association with cleft lip and palate. Am J Hum Genet 6:244-256, 1954 3. Soricelli DA, Bell L, Alexander WA: Congenital fistulas of the lower lip. Oral Surg 21:511-516, 1966 4. Stewart RE, Prescott GH (eds): Oral Facial Genetics, 1st Ed. St. Louis, C. V. Mosby Co., 1976, pp 500-662 5. Cervenka J, Gorlin RJ, Anderson VE: The syndrome of
pits of the lower lip and cleft lip and/or palate. Genetic considerations. Am J Hum Genet 19:416, 1967 6. Whitaker LA, Pashayan M, Reichman J: A proposed new classification of craniofacial anomalies. Cleft Palate J 18:161, 1981 7. Fraser FC: The genetics of cleft lip and cleft palate. Am J Hum Genet 22:36, 1970
Volume 7 Number 4 July 1986 313