Dermatology Online Journal

Hereditary hypodontia and onychorrhexis of the fingernails and toenail koilonychia: Witkop's tooth-and nail syndrome.
Edward J. Zabawski Jr., Jack B. Cohen
Dermatology Online Journal 5(1): 3

University of Texas Southwestern Medical Center, Dallas

Abstract

The tooth-and-nail syndrome (Witkop's syndrome) is a rare autosomal dominant ectodermal dysplasia manifest by defects of the nail plates of the fingers and toes and hypodontia with normal hair and sweat gland function. We report a thirteen year-old girl who presented with marked longitudinal ridging of the nail plates of all ten fingers. The toenails were mildly ridged with koilonychia. Her mother's fingers were similarly affected to a lesser degree while her toenails appeared normal. Examination of the child's dentition revealed a hyperplastic frenulum and the absence of one of the usual four mandibular incisors. History provided by the mother described the maternal grandmother and maternal great aunt as having identical nail findings and the presence of only three lower incisors. Hair examination was normal in the mother and child, and no history or findings of sweat gland dysfunction was present. This report describes familial hypodontia, fingernail onychorrhexis, and toenail koilonychia consistent with Witkop's syndrome.

---

Ectodermal dysplasias are a group of hereditary diseases characterized by the absence or impaired function of two or more structures originating in ectoderm, primarily the teeth, hair, nails and glands. The tooth-and-nail syndrome, first described by Witkop in 1965, is a rare autosomal dominant ectodermal dysplasia manifest by defects in the nail plates of fingers and toes and hypodontia, with normal hair and sweat gland function.[1] Typically, toenails are more severely affected than fingernails, and in some instances, nail plates are absent at birth1. We report a case of tooth-and-nail syndrome in an adolescent female with similarly affected immediate ancestors.

Case Report

Figure 1
There is marked onychorrhexis of the nail plates of a 13 year-old girl

A thirteen year-old girl presented for evaluation of an acute eruption, eventually diagnosed as pityriasis rosea. In the course of her examination, striking longitudinal ridging of the nails on all ten fingers was noted (Figure 1). No pitting, discoloration or other abnormalities were observed. There was koilonychia of the nail plates of the great toes of both feet, with mild transverse ridging (Figure 2). According to her mother, the child's fingernails had prominent ridges since birth. Examination of her scalp revealed normal hair quality, quantity and structure. The bony structure of her face appeared normal. No personal or family history of heat intolerance or inability to sweat was elicited. The child's maternal grandmother and maternal great aunt were reported to have identical fingernail findings. Examination of the mother's fingernails revealed less severe longitudinal ridging. Examination of the child¹s oral cavity revealed normal permanent teeth, but only three lower (mandibular) incisors were present (Figure 3). Her mandibular labial frenulum was hyperplastic. The mother reported her own teeth to be normal, but declined examination. The mother also reported that she knew her child had only three mandibular incisors and that both the maternal grandmother and maternal great aunt possessed identical defects.

Figure 2	Figure 3
Note the koilonychia of the great toenails. Mild transverse ridging is also present.	The patient has only three mandibular incisors. Note the hyperplastic frenulum.

Comment

More than one hundred ectodermal dysplasias have been described. Defects of teeth and nails with normal hair and sweat gland function, inherited in an autosomal dominant fashion, were first described by Witkop.[1] Hypodontia and nail dysplasia are typical features. Several kindreds have been described with variable dental defects, including pegged teeth, wide dental spacing, or absent teeth (hypodontia).[2] Typically, dental anomalies are less severe in the tooth-and-nail syndrome when compared to the more common x-linked recessive hypohidrotic ectodermal dysplasias.[1] Absent maxillary incisors, second molars, and maxillary canines are the most common missing teeth.[1] Defects in primary teeth may be so mild that no abnormality is noted until the permanent teeth fail to erupt.[1] Nail defects are typically most notable during childhood, and they often disappear in adulthood.[1] Nail plates may be congenitally absent. Toenails are typically more severely affected than fingernails, and they most commonly exhibit thin nail plates and koilonychia.

Although hair defects are not specifically associated with Witkop's syndrome, some patients have hair that is of fine in texture or diffusely thin.[1,3] Whether mild hair defects are a feature of this disorder has been disputed,[3] but neither marked hypotrichosis nor areas of alopecia are a feature.

Anomalies of facial topography, such as frontal bossing, depressed nasal ridges, and everted lips, commonly seen in patients with x-linked recessive ectodermal dysplasia, are not seen in Witkop's syndrome. Sweat gland function is normal. In general, the features of the tooth-and-nail syndrome are much less severe than those in more common ectodermal dysplasias, so that it may be easily missed by an unsuspecting clinician.

The genetic defect in Witkop's syndrome has not been identified. As with other genodermatoses, no specific treatment is available, although cosmetic dentistry can improve bothersome dental defects. Children with conical teeth, hypodontia or anodontia without some other readily apparent etiology should undergo a detailed examination to determine if abnormal nail plates on the fingers and toes are present. Obtaining a family history is important, as Fried's tooth-and-nail syndrome looks very similar to Witkop's tooth-and-nail syndrome clinically but is inherited in an autosomal recessive fashion. Other ectodermal dysplasias with defects confined to the nails and teeth include deafness and onychoosteodystrophy with retardation (DOOR)[4] syndrome and Curry-Hall syndrome,[5] although these children are characteristically more severely affected. Toddlers and young children who may be manifesting one of these diseases should be evaluated by a neurologist for retardation and seizures (Curry-Hall) and an audiologist. Genetic counseling is recommended, as is regular evaluation by a pediatrician.

Conclusion

A thirteen year-old girl with Witkop's tooth-and-nail syndrome, a rare autosomal dominant ectodermal dysplasia, is reported. Her family history is consistent with autosomal dominant inheritance. She demonstrates hypodontia and nail dysplasia, but no features associated with other ectodermal dysplasia syndromes.

References

1. Hudson CD, Witkop CJ Jr.. Autosomal dominant hypodontia with nail dysgenesis. Oral Surg 1975;39:409-423.

2. Witkop CJ, Brearley LJ, Gentry WC. Hypoplastic enamel, onycholysis, and hypohidrosis inherited as an autosomal dominant trait: A review of ectodermal dysplasia syndromes. Oral Surg 1975; 39:409-421.

3. Chitty LS, Dennis N, Baraitser M. Hidrotic ectodermal dysplasia of hair, teeth and nails: case reports and review. J Med Genet 1996 Aug; 33(8)707-10.

4. Nevin NC, Thomas PS, Calvert J, Reid MM. Deafness, onycho-osteodystrophy, mental retardation (DOOR) syndrome. Am J Med Genet 1982 Nov;13(3):325-32

5. Shapiro SD, Jorgenson RJ, Salinas CF. Brief clinical report: Curry-Hall syndrome. Am J Med Genet 1984 Mar;17(3):579-83