DNA Methylation Analysis of Ribosomal DNA in Adults With Down Syndrome

Area of Science:

• Epigenetics
• Genetics
• Molecular Biology

Background:

• Ribosome biogenesis is crucial for cell metabolism.
• Down syndrome (DS) involves trisomy 21, leading to extra ribosomal DNA (rDNA) copies.
• Epigenetic regulation of rDNA in adults with DS remains understudied.

Purpose of the Study:

• Investigate DNA methylation (DNAm) of rDNA units in adults with DS.
• Evaluate RNA45S precursor ribosomal RNA expression in adults with DS.
• Explore the epigenetic landscape of rDNA in the context of Down syndrome.

Main Methods:

• Targeted deep-sequencing for DNAm analysis of rDNA in whole blood.
• Analysis of 69 adults with DS and 95 euploid controls.
• Evaluation of RNA45S expression in peripheral blood mononuclear cells (PBMCs).

Main Results:

• RDNA promoter exhibits a trend towards hypermethylation in adults with DS compared to controls.
• Significantly lower intra-individual epihaplotype diversity observed in the DS group.
• Higher inter-individual variability in rDNA epigenetic profiles noted in the DS group.
• Reduced RNA45S expression detected in adults with DS.

Conclusions:

• Adults with DS display a rearranged epigenetic profile of rDNA.
• This epigenetic shift may serve as a compensatory mechanism for extra rDNA copies.
• Further research is needed to link rDNA regulation to DS pathogenesis and clinical heterogeneity.