Facial and oral findings in trichorhinophalangeal syndrome type 1 (characteristics of TRPS 1).

~-Yndings ~re reported on 12 members representing five generations of a large family with a history of trichorhinophalangeal syndrome type I. Consistent facial characteristics included; bulbous pear-shaped nose, elongated philtrum, tented alae, scant eyebrows in the temporal portion, large protruding ears and a thin upper tip. Oral findings included; congenital absence of teeth, considerable delay in root and crown development and isolated cases of hypoplasia, malocclusion, abnormal tooth shape and extensive ca~es. Introduction GiedionI in 1966 first identified a syndrome characterized by a triad of findings: sparse hair, bulbous nose, and short deformed fingers. He coined the term trichorphinophalangeal syndrome (TRPS). Since that time a number of reports ~s have described various aspects of this condition .and demonstrated that it is inherited in an autosomal dominant fashion. The most consistent features are a peculiar facies with a bulbous, pear-shaped nose, fine scalp hair, sparse temporal portion of the eyebrows, and shortening of the phalanges. These changes in finger morphology are attributed to an early and uneven closure of growth plates. ~g Radiologically the epiphyses of the middle phalanges of the second, third, and fourth digits have a cone-shaped appearance33,4 Frequently, these patients also have short stature and multiple skeletal abnormalities. The following findings have also been reported: growth and mental retardation, brachydactyly, tented nares, prominent elongated philtrum, narrow palate, 4 rnicrognathia, mandibular retrognathia, and midface hypoplasia, TM hip disease, m2 kyphoscoliosls and pectus carinatum,7 and cardiovascular abnormalities. 4,~3 The present study involved a family that spans five generations, with affected individuals ranging in age from birth to 70 years {Figure 1). This family has been thoroughly evaluated by multiple medical and dental specialists and three published reports have presented specific findings?*~g A radiographic study" of this family reported a high incidence of hip and other skeletal abnormalities including scoliosis, kyphosis and pectus carinatum. The authors concluded that the syndrome most probably represents a condition which results from abnormal maturation of the epiphyses and growth plates. A cephalometric study by King and Frias ~ of both affected and unaffected members of this same family reported the following findings in affected individuals: 1) the posterior cranial base significantly shortened and deflected superiorly; 2) the mandibular body and ramus were shortened; and. 3) there was a shortening of the posterior face height and steep inclination of the mandible resulting from the anterior and superior positioning of the mandibular articulation with the cranium and the short ramus. The authors stated that, with the exception of the shortened ramus, "the craniofacial alterations associated with the trichorhinophalangeal syndrome can be attribted to a primary defect in endochondral growth of the skull." In a comprehensive evaluation of this same family, Frias et al. Is focused on the genetic aspects of the syndrome, noting a remarkable variability in expression. Normal intelligence was found in all affected individuals and short stature in 17 of the 23. They also reported spinal abnormalities, rarely mentioned in previous reports, and recommended that detailed radiologic evaluation of parents and siblings of affected individuals be preformed prior to genetic counseling for these families. Methods and Materials The sample consisted of 37 members of a single kindred for a history of TRPS, ranging in age from three to 66 years. Older members of this group were excluded from the final study group since they were endentulous. The 12 .subjects included in the study group had clinical and radiological findings consistent with the diagnosis of TRPS type I. They ranged in age from three to 31 years. 348 TRICHORHINOPHALANGEAL SYNDROME TYPE 1 : Bennett et al. Each subject received a visual dental examination during which a series of 2 x 2 color slide photographs (full face, profile, anterior intraoral, maxillary arch and mandibular arch), and a cephalometric and panographic x-ray were obtained. Cephalometric findings are reported in a previous study.’5 The records were arranged in a large notebook alphabetically according to the patients’s last name. Information on affected and unaffected individuals was recorded in a separate folder. A score sheet containing the areas to be examined was developed to include all findings previously reported. Areas shown on Table 1 were evaluated by two examiners {the first and second authors). In addition, the dental ages of seven subjects were calculated from panoramic x-rays using a technic to assess crown and root development described by Nolla? 7 Both examiners evaluated the records and scored each area. The second examiner had no knowledge of whether the patient w~ an affected or unaffected subject. The results of the two examiners were compared and differences reconciled by joint review of the records in question.