Background
Bloom syndrome (BS) is a rare autosomal recessive chromosome instability disorder. The main clinical manifestations are growth deficiency, telangiectasic facial erythema, immunodeficiency, ...and increased risk to develop neoplasias at early age. Cytogenetic test for sister chromatid exchanges (SCEs) is used as a diagnostic marker for BS. In addition, most patients also present mutations in the BLM gene, related to defects in the DNA repair mechanism. However, the molecular mechanism behind the pathogenicity of BS is still not completely understood.
Methods
We describe two patients confirmed with BS by SCE and molecular analysis. Also, we performed the gene expression profile by the RNA‐seq methodology in mRNA transcripts for differential gene expression analysis using as a biological condition for comparison BS versus health controls.
Results
We detected 216 differentially expressed genes related to immunological pathways such as positive regulation and activation of B cells, immune effector process and absence of difference of DNA repair genes expression. In addition; we also observed differentially expressed genes associated with apoptosis control, such as BCL2L1, CASP7, CDKN1A, E2F2, ITPR, CD274, TNFAIP6, TNFRSF25, TNFRSF13C, and TNFRSF17.
Conclusion
Our results suggest that the combination of altered expression of genes involved in signaling pathways of immune response and apoptosis control may contribute directly to the main characteristics observed in BS, such as recurrent infections, growth failure, and high risk of cancer. Transcriptome studies of other instability syndromes could allow a more accurate analysis of the relevant gene interactions associated with the destabilization of the genome. This is a first description of the profile of differential gene expression related to immunological aspects detected in patients with BS by RNA‐seq.
We investigate two patients with Bloom´s syndrome that presented immunological deficiency that was confirm by differential gene expression analysis by RNA‐seq using Illumina platform. The analysis showed an unexpected highly complex transcriptional profile with downregulated differentially expressed genes associated to activation and regulation of immune pathways and absence of difference of DNA repair genes. This is a first description of the profile of differential gene expression related to immunological aspects detected in patients with SB by RNA‐seq.
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