A Pilot study to Analyse IDH 1/2 (Isocitrate Dehydrogenase) Gene Mutations by PCR Sequencing in Chondrosarcomas and Osteosarcomas with Cartilaginous Differentiation

Jesina Samuel, (2020) A Pilot study to Analyse IDH 1/2 (Isocitrate Dehydrogenase) Gene Mutations by PCR Sequencing in Chondrosarcomas and Osteosarcomas with Cartilaginous Differentiation. Masters thesis, Christian Medical College, Vellore.


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INTRODUCTION: The diagnosis of primary tumours of the bone by histopathology faces many practical difficulties. Since they are rare, many pathologists lack sufficient experience in diagnosing them. Many lesions of the bone show overlapping morphological features in histology and the pathologist should be familiar with the clinical presentation and imaging findings in order to give the final diagnosis. There can be morphological similarities between neoplastic conditions and some non-neoplastic diseases which makes their accurate diagnosis challenging. OBJECTIVES: To analyse the IDH1/2 mutational profile among cases of chondrosarcoma and osteosarcoma with cartilaginous differentiation (CBOS) and to correlate the mutational pattern with clinico-pathological parameters. METHODS: IDH gene mutation analysis by PCR sequencing was done on the archived blocks of chondrosarcomas and CBOS, diagnosed in our department from December 2014 to October 2018. Demographic and clinical details were obtained from the clinical workstation and analysed. Descriptive statistics were reported using mean. IDH1/2 mutation was reported using frequency. Chi square/ Fischer’s exact test were done to associate the outcome variable with the categorical variables. RESULTS: Sixty cases were in our study - 41 chondrosarcomas and 19 CBOS. The mean age at presentation for chondrosarcoma was 43 years. All CBOS were below 40 years of age. There was slight male preponderance in both cases and long bones were the most common sites. 36 chondrosarcoma cases had complete mutational results which revealed that 9/36 (25%) of the chondrosarcomas harbored a somatic mutation in either IDH1 or IDH2.The majority of mutations were found in the IDH1 gene (n = 7, 70%) specifically, R132H, R132G and R132S. In IDH 2 gene, R172K mutations were observed. One case showed mutation in both IDH1 and IDH2 genes. None of the 19 CBOS harbored a mutation in either gene. CONCLUSION: In conclusion, this is the first mutational analysis of chondrosarcomas in our population. As against western literature: 1. Mutation positive cases were only 25%. 2. IDH1R132H was the most prevalent mutation. 3. IDH1R132C mutation was not seen. 4. Higher percentage (30%) of IDH 2 gene mutations was identified. Thus IDH1 or IDH2 mutation can potentially be a biomarker to aid in distinguishing chondrosarcoma from CBOS.

Item Type: Thesis (Masters)
Additional Information: 201713353
Uncontrolled Keywords: IDH, mutation, chondrosarcoma, CBOS.
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 29 Jan 2021 17:58
Last Modified: 29 Jan 2021 17:58
URI: http://repository-tnmgrmu.ac.in/id/eprint/13431

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