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yiluyucheng / dnaMethyAge

Predict epigenetic age from DNA methylation data
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Negative values for PhenoAge Clock #10

Open wwangbl opened 6 months ago

wwangbl commented 6 months ago

Hello,

Thanks for your work! I have a question regarding PhenoAge (LevineM2018). In my calculations using methyAge, I got negative values when the chronological age is small (normally occur when chronological age is below 10). May I know what may cause this and whether this is normal?

Furthermore, I'd like to know what imputation methods are used when the input data has missing entries.

Thank you!

yiluyucheng commented 6 months ago

It is normal to get negative values from PhenoAge. For imputation, the package replaces NAs with samples mean or golden reference which is mean beta values generated from GSE55763.