DAG2 is one of Lifelines' additional assessments performed in collaboration with the UMCG department of genetics (see also: DAG1 and DAG3). DAG is the abbreviation of DArmGezondheid, or “Gastrointestinal health” in Dutch.
DAG2 comprised of the collection and analyses of samples and data following the same protocol as DAG1, in a small group of Lifelines participants that had previously been included in the GoNL project. For these participants, the whole genome sequence was analused.

DAG2 included approximately 100 Lifelines participants that had been selected for the GoNL project. In this consortium the whole genomes of 250 Dutch parent-offspring families are sequenced. Lifelines contributed samples of 55 trio’s (165 samples total) to the GoNL project.In total five biobanks contributed samples (Lifelines, Leiden Longevity Study, Netherlands Twin Registry, Rotterdam Study and Rucphen Study). Samples were sequenced on an Illumina HiSeq 2000 instrument (91-bp paired-end reads, 500-bp insert size), and reads were aligned on the UCSC human reference genome build 37 using Burrows-Wheeler Aligner (BWA) 0.5.9-r16 (Li and Durbin, 2010; Li and Durbin, 2009). Samples were also genotyped on the Illumina Immunochip as well as on at least one other genotyping chip. GoNL data can be requested through the GoNL website: www.nlgenome.nl.

Sample and data analyses is similar to DEEP (a.k.a. DAG1) and DAG3, except for the genetic data. Since whole genome sequences are available for the Lifelines-GoNL participants, SNP genotyping was not necessary for the DAG2 cohort.