Identifying related individuals using --rel-cutoff

[cls]

Hi,

I've used Plink 1.9 to create a genetic relationship matrix (GRM) in a cohort which includes a large amount of family relatedness. I would like to extract a list of individuals that are not closely related. I was planning to use --rel-cutoff to extract a list of individuals removing one individual of each pair of close relatives (1st-degree, up to 2nd-degree, and up to 3rd-degree for comparison).

Please may I check the expected values to identify related individuals here - would this be 1st-degree (0.5), up to 2nd-degree (0.25) and up to 3rd-degree (0.125)? Does Plink 1.9 create GRMs containing relatedness coefficients or kinship coefficients?

Any help with this would be very much appreciated!

Thank you, Chloe

[Christopher Chang]

Use plink 2.0's more reliable --king-cutoff flag for this.

[cls]

Thank you very much!