RESUMO
OBJECTIVE: To perform a phenotypic characterization of the dento-osseous anomalies in a Brazilian family with Familial Adenomatous Polyposis (FAP) and to investigate the adenomatous polyposis coli (APC) causative variant. DESIGN: The study included a family of 14 individuals (Group A: affected; Group B: non-affected). The frequency of radiographic findings in both groups was evaluated according to the Dental Panoramic Radiograph Score (DPRS) diagnostic method. The accuracy and reproducibility of DPRS were tested. The DNA was isolated from the index patient's saliva and submitted to whole-exome and Sanger sequencing approach. RESULTS: DPRS ≥ 7 was observed in 80 % of Group A but in none of Group B. The most common findings in Group A were dense bone islands (60 %), hazy sclerosis (40 %), osteomas (40 %), and supernumerary tooth (20 %). DPRS has proved to be a reliable method while DPRS ≥ 5 and DPRS ≥ 7 were taken as positive for FAP, and reproducible diagnosis test considering that the evaluators correctly identified the affected patients (Kappa agreement>0.8, p = 0.002). A nonsense heterozygous mutation in the APC gene (c.1370C > G; p.Ser457*) of the index case was detected. CONCLUSION: FAP patients have a higher frequency of dento-osseous anomalies (p = 0.005). Bone abnormalities were more prevalent than dental anomalies (p = 0.001). Thus, FAP patients should be referred for dental examination and genetic counseling to perform early diagnosis of dento-osseous anomalies and evaluate the implications of the molecular findings in each particular family.
Assuntos
Polipose Adenomatosa do Colo , Dente Supranumerário , Polipose Adenomatosa do Colo/diagnóstico por imagem , Polipose Adenomatosa do Colo/genética , DNA , Humanos , Radiografia Panorâmica , Reprodutibilidade dos Testes , Dente Supranumerário/diagnóstico por imagem , Dente Supranumerário/genéticaRESUMO
OBJECTIVE: The aim of this longitudinal study was to characterize the dento-osseous phenotype of eleven familial adenomatous polyposis (FAP) patients and twenty-two family members from four Brazilian families who were followed over nine years and to investigate adenomatous polyposis coli (APC) gene variants using a targeted next-generation sequencing approach. MATERIALS AND METHODS: Medical and dental history, oral examination, and panoramic radiography were performed to diagnose and follow up the dento-osseous anomalies. The anomalies were evaluated following the validated diagnostic tool dental panoramic radiographic score (DPRS), a system developed for high-risk FAP patients. Patients diagnosed with dento-osseous anomalies underwent cone-beam computed tomography. For genetic analysis, DNA was isolated from patients' saliva. RESULTS: Dento-osseous anomalies were identified in ten of the eleven FAP patients by panoramic radiograph evaluation. DPRS ≥ 7 (significant changes) was found in 81.8% (9/11) of FAP patients. The follow-up showed an increase in osseous jaw lesions in two young patients during adolescence. Dento-osseous anomalies were not found in non-FAP patients. A novel heterozygous nonsense pathogenic variant in APC exon 5 (c.481C > T; p.Gln161*) was identified in family 2, and a heterozygous splice-site pathogenic variant was identified in family 1 (c.532-1G > A). CONCLUSION: Our study expands the mutation spectrum of the APC gene and provides evidence that dento-osseous screening by imaging is a putative tool for early diagnosis of FAP. Also, the detection of dento-osseous anomalies in young patients with increasing osseous lesions during adolescence highlights the need for dental follow-up of high-risk FAP children. CLINICAL RELEVANCE: Dental radiographs are important for the screening and the follow-up of dento-osseous anomalies associated with FAP. It can also contribute to the early diagnosis of the disease.