A study has unearthed nearly 2 million instances of additional and missing stretches of DNA from the genomes of 79 people. The analysis of archived genome sequences revealed insertions and deletions (indels) ranging from 1 to 10,000 base pairs in length. Almost two-thirds have not been reported before.

Researchers have struggled to identify such small, but important, variations in the human genome. More than 2,000 of the indels found by Scott Devine at the University of Maryland in Baltimore and his team were in the coding regions of known genes. The authors developed a chip-based assay for quick identification of about 10,000 of the smaller indels. Such chips could aid in interpreting the results of other genomic studies.

Genome Res. doi:10.1101/gr.115907.110 (2011)