TERT promoter mutations: a genetic signature of benign and malignant thyroid tumours occurring in the context of tinea capitis irradiation

摘要

Objective The aim of this study is to evaluate the frequency and molecular characteristics of TERT p mutations in thyroid adenomas and carcinomas occurring in the low-dose radiation exposure tinea capitis setting. Design and methods Twenty-seven patients with 34 well-differentiated thyroid carcinomas and 28 patients with 29 follicular adenomas diagnosed in a Portuguese tinea capitis cohort were studied. Blood samples were obtained from all the patients. Screening for TERT p mutations was performed by PCR amplification followed by Sanger sequencing. A series of 33 sporadic thyroid adenomas was used as control. Results TERT p mutations were detected in six of the 28 patients with adenoma (21.4%) and in four of the 27 patients with carcinoma (14.8%). Three tumours (two carcinomas and one adenoma) had the tandem mutation ?124/?125 GG>AA (30.0%), whereas the remaining seven had the ?124G?>?A. The 20.7% frequency of TERT p mutations in adenomas contrasts with the absence of mutations in the adenomas from the control group and from most series on record, whereas the one found in carcinomas (11.8%) is similar to those reported in the literature for sporadic carcinomas. Conclusion TERT p mutations, including the tandem mutation ?124/?125 GG>AA not described previously in thyroid tumours, appear to represent a genetic signature for thyroid tumours in patients submitted to low-dose X-ray irradiation. The high frequency of TERT p mutations in the adenomas of our cohort contrasts with their absence in sporadically occurring, as well as in adenomas of the Chernobyl series.