Trichorhinophalangeal dysplasia (Giedion syndrome). A case report

Trichorhinophalangeal syndrome type 1 (Giedion syndrome): A case report with literature review

INTRODUCTION AND OBJECTIVES

Trichorhinophalangeal syndrome (TRPS) is a rare multisystem disorder characterized by abnormalities in the hair (tricho), nose (rhino), and digits (phalangeal). A variety of nonspecific intraoral findings have been reported in the literature, including hypodontia, delayed tooth eruption, malocclusion, a high-arched palate, mandibular retrognathia, midface hypoplasia, and multiple impacted teeth. In addition, supernumerary teeth have been detected in several persons with TRPS, especially type 1. This report describes the clinical manifestations and dental management of a TRPS 1 patient with multiple impacted supernumerary and permanent teeth.

PATIENT

A 15-year-old female patient visited our clinic with a known medical history of TRPS 1 with laceration of the tongue caused by teeth eruption in the palate.

RESULTS

Radiographic images showed a total of 45 teeth: two deciduous, 32 permanent, and 11 supernumerary teeth. Six permanent teeth and 11 supernumerary teeth in the posterior quadrants were impacted. Four impacted third molars, supernumerary teeth, retained deciduous teeth, and impacted maxillary premolars were removed under general anaesthesia.

DISCUSSION AND CONCLUSIONS

This case suggests that all patients with TRPS should undergo full clinical and radiographic oral examination and should be informed about the disease and the importance of dental counselling.

TRPS1 mutation associated with trichorhinophalangeal syndrome type 1 with 15 supernumerary teeth, hypoplastic mandibular condyles with slender condylar necks and unique hair morphology

Trichorhinophalangeal syndrome type 1 (TRPS1; Online Mendelian Inheritance in Man #190350) is an autosomal dominant disorder caused by mutations in TRPS1. We report a Thai male with TRPS1 who carried a c.1842C>T (p.Arg615Ter) mutation. He had 15 supernumerary teeth, double mental foramina, hypoplastic mandibular condyles with slender condylar necks and unique ultrastructural hair findings. Body hair was absent. The hair in the area of a congenital melanocytic nevus had a greater number of hair cuticles than normal. Occipital hair had abnormal hair follicles and cuticles. The scale edges of the hair cuticles were detached and rolled up. Hypoplastic mandibular condyles with slender condylar necks, double mental foramina and the rolled up edges of hair cuticles have not been reported in patients with TRPS1.

Making extra teeth: Lessons from a TRPS1 mutation

A Thai mother and her two daughters were affected with tricho-rhino-phalangeal syndrome type I. The daughters had 15 and 18 supernumerary teeth, respectively. The mother had normal dentition. Mutation analysis of TRPS1 showed a novel heterozygous c.3809_3811delACTinsCATGTTGTG mutation in all. This mutation is predicted to cause amino acid changes in the Ikaros-like zinc finger domain near the C-terminal end of TRPS1, which is important for repressive protein function. The results of our study and the comprehensive review of the literature show that pathways of forming supernumerary teeth appear to involve APC and RUNX2, the genes responsible for familial adenomatous polyposis syndrome and cleidocranial dysplasia, respectively. The final pathway resulting in supernumerary teeth seems to involve Wnt, a morphogen active during many stages of development. © 2016 Wiley Periodicals, Inc.