Dental Findings in Gapo Syndrome: Case Report

This article reports the case of a young female adult with GAPO syndrome who presented as a peculiar dental finding unerupted primary and permanent dentitions, which resembled total anodontia on clinical examination. A cephalometric analysis was performed to investigate the alterations in facial bone development. This is the 9th GAPO syndrome case reported in a Brazilian patient.


INTRODUCTION
GAPO syndrome is a very rare genetic disorder with approximately 30 cases reported worldwide.GAPO is the acronymic designation for a complex of growth retardation, alopecia, pseudoanodontia (failure of tooth eruption) and progressive optic atrophy.It seems to have an autosomal recessive pattern of inheritance but its etiology is not yet well understood (1).This condition was first described by Andersen and Pindborg (2) in 1947, but it was named GAPO syndrome only in 1984 by Tripton and Gorlin (3).
Patients who suffer from GAPO syndrome may have several abnormalities including wide anterior fontanel, bossed forehead, prominent scalp veins, increased intracranial pressure, micrognathia, protruding lips and auricles, depressed nasal bridge, altered ability to sweat, skin redundancy, hyperextensible joints, hyperconvex nails, umbilical hernia, delayed bone maturation, hepatomegaly, hypoplasia of the genitalia and mammary glands, and irregular gonadal function.
Eight cases have been described in Brazil.This paper reports the dental findings in a Brazilian young adult diagnosed with GAPO syndrome.

CASE REPORT
A 24-year-old female patient was referred for assessment of oral abnormalities after being diagnosed with GAPO syndrome by the department of Genetics of the Clinics Hospital of Porto Alegre, RS, Brazil.On extraoral examination, the patient had alopecia, saddle nose, thickened eyelids and thick lips (Fig. 1), in addition to short stature (1.35 m).Intraoral examination showed that the upper and lower alveolar ridges were thickened in a buccolingual direction and lined with normal mucosa (Figs. 2 and 3).Panoramic radiograph revealed that all primary and permanent teeth were retained (Fig. 4), which explained the increased maxillary and mandibular volumes.Systemic manifestations included hepatomegaly, keratoconus, cardiopathy, scabby lesion of the scalp and early menopause.Ricketts and McNamara cephalometric computed analyses (Fig. 5; Tables 1 and 2) were performed to investigate the relation of the facial bones with the anterior skull base (ASB) and evaluate the syndromerelated alterations.Some measurements could not be made because some of the cephalometric points could not be marked.The maxilla was prominent compared to the ASB and the patient presented a reduced maxillary height.Both the ASB and the mandible were shorter than normal in length.The mandible seemed to have a normal relation with the ASB and the lower segment of the face was higher than normal.The upper lip was larger than normal, and the lower lip was prominent.
The need for a multidisciplinary approach involv-ing Surgery, Prosthodontics and Oral Rehabilitation was discussed with the patient and the placement of a complete denture was presented as the best treatment option for her case.However, the patient refused to undergo the surgical intervention required to allow denture installation and gave up the treatment.She returned only 5 years later complaining of increased volume in the sublingual region and pain every time she ate.The occlusal radiographic examination revealed the presence of a small salivary calculus (Fig. 6) close to the exit of Wharton's duct orifice, which could be easily removed due to its location.It was also observed the root of a tooth projected out of the cortical bone in the lingual surface of the mandible.However, the patient denied any painful symptomatology.After removal of the salivary calculus, the patient had total resolution of the symptoms.6) finally reported this case as being GAPO syndrome, based on the short stature, alopecia and pseudoanodontia present in both patients.In 1984, Gagliardi et al. ( 7) documented the case of 3 Brazilian siblings that had also consanguineous parents.Silva (8) presented a female patient whose parents were unaffected and apparently nonconsanguineous.These Brazilian cases seemed to belong to four distinct families.In 2005, Rim and Marques-de-Faria (9) described the ophtalmic aspects of two sisters with GAPO syndrome from consaguineous parents.
The patient described in this article had the typical signs and abnormalities of GAPO syndrome.Alopecia was observed in her eyelids, eyebrows and head (Fig. 1).
The dental findings observed in this patient were quite interesting.The pseudoanodontia that resulted from the unerupted primary and permanent teeth caused an increase in bone ridge volume in a buccolingual direction, as shown in the occlusal radiograph.This condition hindered the installation of dentures.Surgical removal of the teeth, even if partial, was deemed too complicated because the teeth were ankylosed (10).In   addition, in spite of all efforts, the patient strongly refused to have her case studied by a multidisciplinary team, which could have improved her esthetic and functional condition.The major complain was the volume increase and pain in the sublingual region caused by a salivary calculus, which was resolved.
A cephalometric analysis was performed because none of the previous reports have done so, probably because there has not been too much interest in investigating the orodental manifestations of this syndrome.Cephalometric analysis should be conducted in further GAPO syndrome cases in order to address new characteristic of this disorder.

Figure 2 .
Figure 2. Thick upper alveolar ridge without any erupted tooth.

Figure 4 .
Figure 4. Panoramic radiograph revealing the presence of several impacted primary and permanent teeth.

Figure 3 .
Figure 3. Intraoral view showing ower alveolar ridge without any erupted tooth present.

Figure 1 .
Figure 1.Lateral view of the face.

Table 1 .
Ricketts landmarks used for cephalometric analysis.

Table 2 .
McNamara landmarks used for cephalometric analysis.