Straight lines – the art of drawing pedigrees using kinship2

Do you still draw your pedigrees by hand? Or generate them using some website, take a screenshot of it (with Photoshop) and paste it into a Powerpoint file that you convert to PDF, send it by mail to a colleague, who then tries to extract the information into a text file representing the pedigree structure in a computer readable format?

Crooked arguments. During our recent NGS workshop I tried to convince the participants that first constructing a text file and then having the pedigree drawn “automatically” is a better approach. To my honest surprise, everybody agreed and actually enjoyed working through the tutorial using the fabulous kinship2 package in R. It would have been perfect except for that only little kink. I hadn’t noticed it even myself but the participants who draw pedigrees on a regular basis all complained about a little bend in the line connecting the primary couple with their children, which appeared consistently in all pedigrees. The authors explained the situation in response to a mail I sent them and found a quick solution that will now draw straight lines in their current package.

Example pedigrees from the kinship2 package. Real pedigrees don't contain names.

Example pedigrees from the kinship2 package. Real pedigrees don’t contain names.

So, there’s no reason left to not assemble your pedigrees properly in the first place and have them drawn by this fine package.

Roland Krause