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What we learned......
• ALL euploid blastocysts showed normal DNA methylation @ 50%.
• Trisomy blastocysts, while aberrant, still have some combination of repression and
expression (methylation vs. non‐methylation).
• Monosomy blastocysts have ALL or NOTHING (100% methylation = no expression!) leading to a possible explanation for their reduced implantation potential.
• Imprinted genes are critical for normal embryo development. Aneuploid blastocysts have compromised imprinted methylation, which could lead to Imprinting Disorders if transferred.
This data supports euploid embryo transfer during infertility treatments.
Denomme et al, 2016
In Conclusion......
• Trisomy blastocysts have:
 no global methylation alterations and are more similar to euploid blastocysts.
 the transcriptome is compromised compared to euploid but to a lesser extent in trisomy
15 than in trisomy 11, which may explain their observed implantation potential.
 trisomy blastocysts have some combination of repression and expression (methylation
vs. non‐methylation) of imprinted genes.
• Monosomy blastocysts do not successfully implant and are compromised compared to euploid and trisomy with:
 hypomethylation on the chromosome of error
 compromised global transcriptome
 for imprinted genes monosomy blastocysts have ALL or NOTHING (100% methylation
= no expression!), further contributing to their reduced implantation potential.
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