GTEx donors are identified through low-post-mortem-interval (PMI) autopsy or organ and tissue transplant settings. To compare the quality of results from autopsy vs. surgically derived tissue, a small subset of tissue types routinely discarded during a surgical amputation, such as skin, fat, and muscle, are also being collected. In addition, peripheral blood samples are collected and used as both a source of DNA for whole-genome single-nucleotide polymorphism (SNP) and copy number variant (CNV) genotyping and to establish lymphoblastoid cell lines. Skin samples are collected from the same region of the lower leg both for measurement of gene expression and to establish fibroblast cultures. Quantification of gene expression is derived primarily from massively parallel sequencing of RNA, but some pilot-phase tissues were analyzed both by sequencing and by gene expression array to enable a technology comparison. eQTLs will be identified and made accessible to the scientific community through the National Center for Biotechnology (NCBI) GTEx database and a GTEx data portal. In addition, the GTEx raw data will be made available through the database of Genotypes and Phenotypes (dbGaP) on a periodic basis.
