27 research outputs found
Disruption of the HIF-1 pathway in individuals with Ollier disease and Maffucci syndrome.
Ollier disease (OD) and Maffucci Syndrome (MS) are rare disorders characterized by multiple enchondromas, commonly causing bone deformities, limb length discrepancies, and pathological fractures. MS is distinguished from OD by the development of vascular anomalies. Both disorders are cancer predisposition syndromes with malignancies developing in ~50% of the individuals with OD or MS. Somatic gain-of-function variants in IDH1 and IDH2 have been described in the enchondromas, vascular anomalies and chondrosarcomas of approximately 80% of the individuals with OD and MS. To date, however, no investigation of germline causative variants for these diseases has been comprehensively performed. To search for germline causative variants, we performed whole exome sequencing or whole genome sequencing of blood or saliva DNA in 94 unrelated probands (68 trios). We found that 7 had rare germline missense variants in HIF1A, 6 had rare germline missense variants in VHL, and 3 had IDH1 variants including 2 with mosaic IDH1-p.Arg132His variant. A burden analysis using 94 probands assigned as cases and 2,054 unrelated individuals presenting no OD- or MS-related features as controls, found that variants in HIF1A, VHL, and IDH1 were all significantly enriched in cases compared to controls. To further investigate the role of HIF-1 pathway in the pathogenesis of OD and MS, we performed RNA sequencing of fibroblasts from 4 probands with OD or MS at normoxia and at hypoxia. When cultured in hypoxic conditions, both proband and control cells showed altered expression of a subset of HIF-1 regulated genes. However, the set of differentially expressed genes in proband fibroblasts included a significantly reduced number of HIF-1 regulated genes compared to controls. Our findings suggest that germline or early post-zygotic variants identified in HIF1A, VHL, and IDH1 in probands with OD and MS underlie the development of the phenotypic abnormalities in a subset of individuals with OD and MS, but extensive functional studies are needed to further confirm it
Top five g:Profiler results for each category from the analysis of 363 genes differentially expressed in three proband fibroblast lines cultured at hypoxia compared to the same three proband fibroblast lines cultured at normoxia.
Analysis was performed using the default settings and selecting the Ensembl ID with the most annotations for each gene name. The p-value cut-off was 0.05 after g:SCS significance adjustment. If number of significant genes in g:Profiler term is greater than 50, n is shown; full lists are available upon request. (PDF)</p
RNA-seq analysis shows differentially expressed genes between proband and control groups.
A. T-SNE shows clusters based on hypoxia treatment and whether the sample is from a proband or a control. B. Heatmap of significant (pTable 1.</p
The numbers of differentially expressed genes with a p-value less than 0.05 are shown for each comparison.
See S1–S4 Tables for full lists of significant differentially expressed genes.</p
g:Profiler results from the analysis of 58 genes differentially expressed in four proband fibroblast lines cultured at normoxia compared to three control fibroblast lines cultured at normoxia.
Analysis was performed using the default settings and selecting the Ensembl ID with the most annotations for each gene name. The p-value cut-off was 0.05 after g:SCS significance adjustment. (PDF)</p
Primer pairs designed for genomic DNA amplification and Sanger sequencing of candidate variants.
(PDF)</p